I always thought it was strange in Oblivion that there was this "evil" group of Necromancers everyone in the Mages Guild despised, but they were happy to teach me how to summon zombies for 300 gold pieces.
I always thought the exact same thing, it's kinda silly, hopefully they think this time and don't do it again.
Anyway, maybe they're bringing back the requirements as well as saying 'You can't join the Necromancer Cult! You work for the Nine Divines you ninny!" or something along those lines, I think that would probably be the best way to implement factions, and perhaps as they did in NV, faction reputations.