The exams are fairly equivalent now that California shaved off a day, and courts regularly let foreign state attorneys appear pro hac vice. I think the problem is likely jurisdictional and administrative. Trying to long arm that Attorney re discipline and hitting his accounts for fees if he loses. The state bar would have to enter a judgment and then have it entered in the foreign state so it could be enforced there.

They're also probably afraid that once reciprocity is granted, a bunch of us will just leave the state, since we could get licensed elsewhere on reciprocity alone.