While the core of the game is fantastic, and while both the new lobby and training mode introduces several nice improvements, everything else just feels half baked at best.
Like the fact that you unlock the ability to change costumes / colors in story-mode, but that mode is stuck on very, very easy, so why would you ever want to replay it? And I say that despite actually rather enjoying those short story beats. Like the fact that survival is a meaningless grind, where you have to fight your way through an army of almost pacifist AIs before you get to the ones who actually fight back. And then when you lose one round, you have to fight all your way back through those pacifist AI to get to where there is a challenge. Not to mention that cosmetic colors are locked behind this grind, where previously you unlocked those simply by using a given character. And that you can't even VS the AI in a proper match, but either have to use those worthless modes, or training mode. Or the fact that several online features were outright broken on launch, not simply overloaded, that integration into Steam (and possible PSN) is extremely poor, with user-searches being basically broken until yesterday. And lets not forget the poor hardware support and lack of configurable keyboard bindings.
And hell, even the improved features that are in the game feel unpolished. An example I just stumpled upon in training mode is the shortcut settings. If you compare the first two entries, these use text to refer to the LS and RS buttons. The next entries use icons for those buttons. What? Nor does training-mode remember your previous settings, unlike SFIV. And while you can filter by connection both for ranked and casual matches, there is no way to filter lobbies, so you just get randoes from the other side of the globe joining your lobby.
All in all, I have no issue understanding why people who did not get this game for online first and foremost would be greatly disappointed with the game. Keep in mind that the road-map in which it was revealed that stuff like the store, trials, and proper lobbies would be missing on launch, was not published until 5 days before the game was released, and was probably never seen by the majority of their costumers. For one thing, this time they did not put the announcement on Steam, unlike previous announcements. Nor does the Steam store or PSN mention these missing features or the road-map, last I checked.
In short, Capcom has failed to properly inform their customers about what would actually be in the game on launch, botched the launch, and are facing a well deserved backlash.