The same as with any other identity politics, really. It makes it really hard to get shit done policy wise, because when you view everything through the lense of identity politics,
every disagreement becomes an attack on
you personally even if it is just an honest difference of opinion. While some things
should be polarizing, probably, identity politics tends to make things needlessly polarizing sometimes, I've found. It is a useful tool definitely, but when it's the only way you approach policy and political action, it often makes you feel really good and validated even while you're failing to achieve a lot of your goals.
Going into it any further than this is going to require more specific examples, which I'm not willing to do since it will derail the hell out of this thread. Sorry.