So, I promise I'm not trying to be disputatious here, disagreeing on so many points--I really am just enjoying discussing this points with another old hand--but two things here:
One, I actually liked Dirge of Cerberus: I think it's one of the more underappreciated games that Square ever made--or at least I remember it that way. Yes it's story was a bit tacked-on to the existing lore in a way that felt redundant and over-the-top, and its villains were two-dimensional and seemed to leap out of the pages of a comic book, but I thought that game did a bloody brilliant job of bringing the environmental design of FFVIII into three dimensions, decades before Remake did it in a frankly less impressive fashion (relative to the time at which each game was made and their comparative budgets). It was also a more than passable shooter on the gameplay front. Of course I realize from your wording that you are probably speaking to it's lackluster plot more than anything--which, yeah, fair enough.
But that leads into my other difference of opinion: I think SCV probably has the most respectable plot of any game in Soulcalibur cannon. Or let me qualify that: I think that Soulcalibur's narrative is bonkers and silly on the whole and that (paradoxically) this has been a part of its success: the early games encouraged you (whether this was intentional on the part of the devs or not) to just give up on any sense that the backdrop to your staged battles between warriors wielding weapons as big as themselves (who never, ever die or so much as suffer serious permanent injury) would have any kind of consistency or firm logic behind it. By being one of the world's most outrageous, nonsensical, inconsistent narratives (even by gaming standards) it did a great job of facilitating the spectacle that was the gameplay and the brilliant character and stage design, which then were beholden to nothing but the devs' imaginations.
But of course we live in a world where something simple and working can never be left alone indefinitely and--largely as a consequence of nerds who did take that whimsical story too seriously--commercial factors and staff turn-over were bound to push the series towards taking itself more seriously than it's legacy of storytelling could ever justify. So the trend has been towards making a more serious and self-consistent story. Well, alright, fine. But we've really only had two games in the series that have attempted to do this in a full-throated fashion: SCV and SCVI. And if I have to pick the one that did it better, it's not even a contest.
SCV, for all it's famously undercut budget, attempted to tell a fairly (in Soulcalibur terms) mature and cogent story with emotional resonance. It did this by actually becoming the first game in the series to (gasp) have longterm consequences for characters and events that weren't instantly reversed the next time you needed one of the same characters to show up on screen for another fight. It actually attempted to have some degree of emotional resonance, told it's story through fairly well produced cinematic techniques, told one fairly cohesive and stripped-down story, and (gasp again) kinda sorta made you feel for some of these characters for once, in a way that has never been justified by the "Here comes a new challenger" slapped together stories of the franchise before or since. Yeah, it's not worth all of the other dubious design choices (particularly the roster shake-up) that were made in that game. But when you stop to look at each individual game and how it told its story, this was clearly the most mature approach any Soulcalibur took, and the closest any game in the series has come to having something we might call narrative depth.
SCVI on the other hand, went in the opposite direction on almost every call when it comes to the design and presentation of the story and has got to be one of the most tedious, trite, obnoxious, poorly told narratives I've ever come across in any genre or medium. It is truly, epically terrible. Once again we go back to an era where the same forty people are constantly running each other through with their weapons and dropping each other off of thousand-foot precipices in increasingly pyrotechnic anime displays, but without any kind of lasting consequence--only this time around there was some perceived need to make several games worth of alternate timelines fit together into one "cohesive" narrative, leading to tortured summary of all the lore previously relegated to cut screens, museum modes, and promotional materials.
And yet, at the same time, presumably out of an understandable perceived need to cloak the fact that all of these "destiny defining" encounters between the principal cast lead to exactly zero lasting consequence for anyone, they are surrounded by the greatest aggregation of filler content ever to be included in a fighter: just unending tiresome hours of banal encounters with cookie-cutter ninjas, bandits, pirates, and corrupted knights, smashed between days worth of pointless dialogue with one-dimensional townspeople/common folk on the road. And even when the plot is more pointed, it's the same old mystical energy / anime / power of destiny nonsense that was perfectly well described in little dialogue tidbits in earlier games. As to the dialogue itself in VI, "tin-earred" doesn't even begin to describe how vacuous and unnatural it all is, or how poorly delivered on the whole.
Worse yet, to accommodate the sheer volume of this insipid nonsense, the entirety of it is delivered through low budget talking-head visual novel format. Because, well, water finds its own level and the level of SCVI's storytelling is precisely that of a dating sim targeted at teenagers and others who never developed more discerning tastes. But what a monumental waste of resources that could have gone into developing content for the actual game itself: characters, stages, weapons, CaS items, netcode improvements, debugging, additional modes of play, cinematics--almost all of the categories of content were lackluster at launch and some remain anemic even now. So instead of legions of Lizardman fans getting their main back, I get to meet five tradesmen in Goa who need the conduit's help in fetch quests, find out exactly how Maxi's crew feel about him (he's a great boss, guys!), and get hamfisted cannon "explanation" for why Ivy dresses like a fetish model. Whooooo....
And here's the thing: I can't even say as it was the wrong call for PS/Namco: they are only cow-tailing to consumerist demands from legions of uber nerds who demand that every game, no matter how predicated in multiplayer competitive play, must always also serve the interests of those interested in single player content--and more to the point, are more than willing to waste their timing organizing to blow up the social media sphere surrounding a game if it dares to try to do something more tailored to a hardcore egaming cohort. One can only pray that the movement to counter bloat in game design will continue to gain some traction--and if it does, let this trashfire of a storytelling experience never be forgotten, because this is truly one of the most hackneyed, laborious narrative experiences I've ever had to wade through by virtue of its proximity to a game I was more or less enjoying on other levels.
Now of course I recognize that SCV kind of cheated/threw SCVI under the bus to do what it did: in order to have a story with some slight impact to it, its developers leveraged it into a place where it was at a clear end point for the story, forcing whoever developed the next game to either undo all of that, and make the events inconsequential afterwards, or just reboot the whole damn thing--because one way or another, you had to bring back the significant majority of the old favorites after SCV's reception. So you can argue that to some extent SCVI was the game it had to be, relative to the point in time it arrived at--in the franchise history and in the timeline of the industry at large. But not even that can account for how bad it's story is, from every angle you can analyze it from, other than maybe giving a hard-on to lore nerds with more tendency towards obsessive compulsive traits than ability for critical appraisal of the quality of the total package.
