why are so many fanfic writers ridiculously hypocritical?

i find it shocking that fanfic writers frequently get pissed at someone else using their OC or ideas in their own fanfic, yet they of course have no qualms using the characters and ideas of published fiction and even when the writer makes it clear they hate fan fiction, fanfic writers think those authors should just suck it up.

personally, i think both fanfic and fanfic of fanfic are okay. but irdg fanfic writers who don't get how hypocritical they are