I wasn't criticising 50/50s in general, just cross-ups. A fair 50/50 is one you actually react to, such as combo strings where the 50/50 setup has enough start-up frames for somebody who knows the animations just has time to react to. Your standard over/under jump cross-up/fakes are also easier to react to based on the jump arc.
When somebody lands straight on your head, it no longer becomes a reaction nor a read but a blind guess. IGAU is a prime example of this, with so many truly ambigious cross-ups existing in the game. Remember the complaints about Scorp's jump 3? Batman's jump 2? Both nearly if not completely impossible to react to. Raven's jump-in 3 is another example (as an unpopular character most people haven't caught on to just how horrific that move is). b23 someone in the corner and they land "under" you. Neutral jump 3 and you'll get a cross-up so ambiguous that even I don't know what side I'm landing on half the time because it's impossible to tell.
Again, I can not stress this enough: cross-ups that land right on top of you are not reads. Done correctly, the person doing the cross-up won't even know which side they're going to land on as it all comes down to the magic pixel. If you can read an opponent who is doing a move that he doesn't know how it will end then kudos to you, I wish I had your powers of precognition. The person crossing-up doesn't need to know what side they land on as anyone doing this kind of setup will follow it up with moves that don't rely on directional inputs (again, sorry to use Raven as an example, but after a cross-up 3 she can just d1 into combo. With a jump-in 2 she can 22 into combo or 3 into combo, again all moves that don't require a f/b input which would require you to either know what side you land on or be able to react to it extremely quickly).
As for anti-airs and the like, did you not notice the insane (and to be honest, quite ridiculous) AA buff nearly every character in Injustice recently got in order to deal with theses? The AA buffs didn't make it any easier to counter the cross-up, but made it easier to hit the opponent before they were on top of you. All of the AA in the world won't help you when put into a setup where you only have a couple of frames to react before the move connects, and unless you have a 1 frame AA that isn't going to work. Case and point: Raven and Batgirl's standing reset - time it right and the jump-in will hit the moment the combo is reset and the opponent is able to react, but the only reaction actually available is to guess which side the magic pixel is on.
MK does not need cross-ups or any other magic pixel blocking technique. Jump-in attacks are good in this game because done well they either lead to big combos on hit or big pressure on block. In a game with such high chip damage, jump-ins are good enough already. High chip damage and throws also help deal with turtle player who just block all day.
Cross-ups: just say no!
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