Because, when player getting comboed have 2 bars it`s obvious he will do breaker, there is no reason to do anything else. Ability to Counter Breaker KI style would add some mind games to combos, what do you think?
If they did that then they would have to make breaking free or counter breaking free, either way the games mechanics aren't designed for it, counter breakers are very much a killer instinct thing, the closest thing would be guilty gears bursts and how they can be baited for even more damage. But again I can't see it working for NRS style games as cool as those mechanics are
The combo breaker system is entirely based around KIs freeflow combo system. It's almost sort of a mixup with every hit because you have to guess what move you think the opponent is going to use. It's a neat mechanic but it wouldn't work with MKs fixed strings as it would make guessing way easier. Granted you could stagger the string but that's not the case for some characters or strings. Sajam made a really cool video explaining KIs combo system and combo breakers and counter breakers.
I'm willing to bet the breaker system is, more or less, here to stay for MK.
No hell no, Fuck no. you knwo what if they sacrifice 20% health and 2 bars as well then go ahead and give them counter break. but io would rather them change game mechanics to make the game more balanced like buffing AA's and Nerfing universal JIP's/NJP's. instead of waisting time and effort on counter Breakers.