Alright, let's get down to it.
It seems that the consensus, at least for the MK side of the community is, it's simply not as good as MK9 and likely never will be without a big redesign. Or at the very least they cannot bring themselves to like this game over MK9 for a variety of reasons. All of these are fair reasons if they are truly your opinions.
So my offer is this. For most MK players, for at least a day or a week, whatever length of time just drop Injustice. Don't look at it, don't play it. Go back to grinding MK9 like you would had Injustice not come out. Just for a short amount of time, pretend Injustice never existed and you're all on MK9 doing what you do.
Now, after said time elapses, ask yourselves a couple of questions. Did you miss playing or watching Injustice at all? Would you really be sad if it wasn't around? If the answer to both of those is no, drop it semi-permanently. Or a better description, drop it until it actually appeals to you again. And then just stay on MK9.
You see I'm getting a sense that really, a lot of MK players are just forcing themselves to play the game at this point either out of obligation, or the fact that it's an NRS game. You should NEVER have to force yourself to play a game. If you do not like it, or there's simply a game you like playing far more, play the different game. It's that simple.
And MK9 deserves love too, it's a solid game that would be helped if MK players went back to grinding on it full time again.
So like I said, take some time out, pretend Injustice doesn't exist, play the hell out of MK9 again. If after that time you don't feel the true need or want to go back to Injustice, you'll know where your heart lies. Better to play the games you truly want than to force yourself to play games you don't want to.
Who knows? Maybe down the line the game will develop into something you actually want. But as of right now, for a good amount of you, it isn't what you want. So don't force it. Let those who DO like this game develop it, they'll do so with or without your input. And if it doesn't develop to your liking, you still have MK9. And if it does, you can always come back. There's no final decision or final destiny for any game.