I did stress from the beginning that Injustice on a whole feels forced and uninspired, and now that sentiment is being realized from a competitive aspect. Live and learn I guess
You mean to say tournament players gravitate towards the top tier? Who would've thunk!
I don't mean to burst your bubble but variety will never get any better, no matter who is nerfed, people will flock to the next best top 5 over and over again until people get bored of watching Lobo, Joker, Lex etc.
The buff the low tier argument has proved to be a pointless endeavour financially for WB too because the same crowd will then complain they're now too good, and end up normalized to be worse than what they were in the first place.
I get what you're saying, and I agree, but let me just go on a rant.
Players of all skill levels don't necessarily mind playing with or against top-tier characters. Players of all skill levels do mind playing with or against braindead strategies.
For example, the reason why Kano was nerfed into oblivion wasn't because he was top-tier: it was because his strategy consisted of only knives and upball with maybe a combo thrown in once in a blue moon. Kabal wasn't touched because he required some heavy execution to perform at his best. Cyrax was nerfed a bit, but the community kept finding ways to keep his resets, plus the mind games of just landing a bomb against certain matchups were difficult. Kenshi was touched only a bit if at all, but that's because he was all about making good reads and reacting to the opponent.
To wrap up the MK segment of this rant: take a look at Raiden. Although not necessarily top or god tier, PL did win, if memory serves me correctly, two EVOs or some other really big tournament with him. And his strategy is complicated in execution: a lot of reads and fast inputs need to be made with the God of Thunder to be successful.
As for top tier in Injustice, I'd have to say only Bats isn't as mindless as Kano was, but that's pretty much because his trait makes up for his lack of great normals.