I like both of them, I don't think either is a genius, and I think both Frank Black and Cobain are on basically the same level. I really think it's underappreciated how much the early Seattle sound was just a fusion of 80s punk and hair metal. If you play Smells Like Teen Spirit and the Breeders "Hellbound" back to back, and you like Nirvana much more, what you really like is Guns n Roses.
There's no shame in that!