It's used for things (like hydrophobic molecules) that avoid other things (in this case water) as if they fear them.

Unless we're doing one of those "literally literally means figuratively" things here in which case... meh?

Just to be crystal clear here, I'm not saying we don't have groups who are anti-X for whatever value of X. I'm saying that recasting (and often miscasting) that antipathy as (maybe masked) fear is counterproductive.