Nothing. I guess they could stop adding new characters to it at some point, but that's not really a real problem because the ones nobody likes such as Jace Fox tend to fall off on their own and disappear.
People always bitch that Batman should be solo but he has practically never been that in his existence. Robin was introduced after less than one year of comics.
>>149671232 (OP)
I generally don't have any problem with the roster before Flashpoint. after flashpoint/New 52 it's become prone to being tampered with too inorganically.
It's hard to keep track when it changes literally every time Batman has a new run, young justice is the only universe that kept things consistent, easy and condensed
