I think some anti-pick bias is also thinly disguised genre bias. Specifically against hard rock, metal, punk, and the thousands of offshoots from them, where pick playing dominates.
This takes a couple forms. One is dismissing music that is simple, as if simplicity is a failing and "real" musicians are only found in more difficult styles. Snobbery again.
And that doesn't fly as a bias against a lot of metal groups of course, which can get into extremely difficult music..Just to pick one ... I'm not a Megadeth fan per se, but I do find them worth an occasional listen and it takes a really intense level of dedicated musicianship to play like Elefson, and it would be absurd to say that his playing would be improved by losing the pick when he's built his whole sound and approach around it. I've read comments of people on YouTube saying he's not really playing bass, he's playing rhythm guitar. To which I say, this is a problem how exactly? His parts fit the music, and if that's what you want to call it, then I'd say he's a better rhythm guitarist than most guitarists.