What he said. I don't really understand that mentality. I mean, why exactly are blondes "generic" when brunettes and redheads aren't?
Through TV and movies (and porn, but let's not go there), the generic one-size-fits-all idea of a hot girl to appeal to men is always a blonde chick with huge tits.
Hence every not so great looking chick thinks they can instantly make themselves hotter by dying their hair blonde. There are a lot of them around too. Therefore the idea of the blonde has become generic. So some people are just tired of the blonde look.
That's just my personal take on it. Obviously there's nothing stopping a blonde from being as hot as a brunette or redhead, but it's just become so common that there are too many generic blondes drowning out the hot ones.
My post is so superficial and shallow my brain hurts. Sorry.