Tbh there's a number of them who'll get all aggressive about "edginess" if they hear criticism of the cartoonier aspects of the series (eg G5).
So I reckon a lot of those types might apply the same attitudes to the practice of liking villains.
Aside from that, I can't really think of any major OP villains who fall under the conventionally attractive category, or who could work as a shippable, I-can-fix-him type* who can be conveniently redeemed in fanfics and mooned over by yaoi fans.
So I guess that would take out a lot of people too.
*
Greenbull actually could have been this if Oda had given him a tragic backstory from the start and made him look more like the actor he was based on.