As I understand it, in the context of a lot of the BL and yaoi of yesteryear, female characters were often there simply to get in the way of the main couple coming together. So a lot of hardcore fujoshi were trained into villainizing any female characters that pop up in a mxm story. Even my own female character got comments expressing suspicion over her motives when she barely appeared for a page (it was annoying).
I don't think that trope is as prevalent nowadays, I certainly hope not.
I don't know about real people hating though. Sounds like a personal problem for those misogynistic folks.