Geek was actually the specific term for a carnival entertainer who bites the heads off of live chickens, before it became a generic term of abuse, before it became a specific term for someone who is passionate about a particular interest.

Also possibly because the original meaning of "weird" has become lost, or at least outmoded, as a result of tarnishing by association with the slur. Nowadays, high school and college literature professors have to preface discussions of Moby-Dick with a disclaimer to the effect that the passage

Well, well, well! Stubb knows him best of all, and Stubb always says he's queer; says nothing but that one sufficient little word queer; he's queer, says Stubb; he's queer - queer, queer; and keeps dinning it into Mr. Starbuck all the time - queer, Sir - queer, queer, very queer. And here's his leg! Yes, now that I think of it, here's his bedfellow!

has nothing to do with sexuality at all.

(Melville knew what he liked, I guess.)

That makes sense.