As I understand it, the problem with that are cases where individuals cannot obtain the proper secondary documents to be issued a REAL ID. Like, CA might be all well and good if you are born in CA, but, what about Texas, for instance? I have a friend who was born there, and if REAL ID comes into effect she will have "male" on it, despite the fact that all her documents currently say female, because Texas will not issue a new birth certificate. And in my experience, states are very stubborn about their secondary documents, so if CA really is complying, won't they have to comply there as well? And I bring up birth certificates, because when I get my ID here, that's the primary document they use.
I might very well be mistaken, but that's my understanding at this point, and why I find it disappointing that CA is not taking an anti stance on this.