And who dafuq are you :) Also dont use caps unnecessarily in the Viola SA :)
SC5 lacked depth in design, the chars, movelists, mechanics all seemed to just a waterdowned version of what they were supposed to be not to mention it is v rigid, almost like BAT on PS.
Obvs Im not expecting all chars to as complex as SC4 Ivy (which I love) but more like SB/SE taki, SC3 Setsuka, Sieg SC2.
I'm the cool Ezio player who happens to know some things about how this game is played. Many characters lost moves yes, but that was because many of the lost moves ranged from extremely situational to flat out useless. Another reason why the movelist changed was to reflect the overall system change with things like unsafe movement, JG, and meter management. By losing superfluous crap just about all the characters have clear methods on how to be played in certain ways and if anything, with things like JG and the high damage, nearly all characters stand a chance...whereas SC4 half the roster was booty.
Also you mention SCV is rigid? Play SCIV right now and say that with a straight face.
SC4 Ivy had a shitton of moves and she was changed drastically (as which happens with just about every new SC, right?) But don't forget to mention that SC4 Ivy bordered on broken given how stupid she was. Can't comment on taki or sets, but SC2 Sieg/Nightmare did not have a lot of depth but rather a lot of moves. Move quantity does NOT equal depth. Competitive SC2 Nightmares usually use just what? 3B and the moves that came from that, hellsweep, throws, the once in a while stance move, aga? Come on man.
SC4 Ivy was a god, and SO much fun. But they had a point. Most people couldn't pick her up because she was too complex for the average user. It's hard to make a style complex because it attracts attention but people get mad if they're too difficult to use.
I think people just assume that characters should be pick-up-and-go type playstyles, kinda like Aeon in SC5. He's got a few combos, but he's mainly pokes. Training won't do a /whole/ lot of good for you there. Then there's Viola who if you don't spend a decent amount of time training, you likely will rarely win a match.
Plenty of scrubs used her and plenty of competitive players used her.