What could prevent a vampire to learn magic related disciplines?

In my actual campaign of Vampire the Masquerade, I actualy made a SPC that know all discipline except all magics related discipline (Blood magic, necromancy, etc…).

As I created it, this made me wonder “What could prevent a vampire to learn magic related disciplines?”

Any edition book can be use to answer, it’s just a curiosity (and maybe to re-use it in other campaign).