I'm by no means a top player.
Hell, I've never even said I was a good player.
What I will say is that while we're all feeling nostalgic about MK9...
Everyone complained about Kenshi.
Everyone complained about Kabal
Everyone complained about Kung Lao.
Everyone complained about Sonya.
Everyone complained about Freddy.
I couldn't sign into this site a day without a Kabal complaint, a Sonya complaint, so on and so forth.
The game wasn't balanced. Maybe Injustice isn't, either. I won't say that it is.
What I will say is that two months into MK9's life, people played the game very differently than they do now. Two months into MK9's life, people actually thought Mileena and Reptile were Top 5 characters. Where are they on the tier list now? Games take time to grow and develop.
I feel like my fundamentals have greatly improved from playing this game. No, I'm serious. I make better reads, counterpoke more, so on and so forth. It's still a very, very hard struggle, but Injustice has made me better.
You can love MK9 all you want. I do, too. However, it's a bit early to say that Injustice solely rewards, "Scrubby play" when we haven't even come up with a universally agreed upon method of selecting stages. Give it time.
Love MK9 better for story, or memories with chums, or simply aesthetics. But this MK9 > Injustice from a gameplay standpoint simply isn't a fair comparison.