in its infancy with its online
Half a year is a little more than an infancy.
Is that the case with most fighting games?
From my experience both Gulty Gear Xrd: Revelator and BlazBlue: Central Fiction were pretty good at launch (at least I didn't have any troubles), so it's not a completely normal thing. At least not for so long.
If this happens with sc6, how many of you will be collectively outraged and start whining from day one like there is no tomorrow?
Nope. Because there is a very big difference exists, Tekken 7 is, essentialy, an online-only game considering how non-existent single player content is. So it's
the only thing they really needed to prepare properly during those
3 years of development during "arcade phase" (balance was constantly tested with profits by normal players at arcades, so it was much less of an issue, despite large roster). Online is basically the only thing T7 has and if it's fucked up - then all of the game is fucked up.
SC6 on the contrary is a proper full game, which you can enjoy (Story, Libra, CaS) even if online is unavailable, which makes this potential situation
much less critical if it would be the case. So I won't have any problems with them taking some time to fix online, let alone outraged (but I guess that's because I'm more of a casual player and even though I would enjoy online battles quite a lot, I'm still not really a competitive player for whom it's a deal breaker situation).