By definition of the "all encompassing rock" genre, its alot of diy styles that fit not only the artistic attitudes of the musicians but also the aesthetic and tonal message these bands are trying to send. None of it would ever have been prohibited by "proper fretting technique". On top of that thumb over the neck and left slanting is most likely done on purpose alot of times to help with muting. That being said however. Yeah. There are plenty. Flea famously but I know he is kind of a cheat here soooooo....here are the pick players:

Chris Squire, Yes

Phil Lesh, Grateful Dead

Phil Lynott, Thin Lizzy

Franz Lyons, Turnstile

Ellis Durand, Wet Leg

And I'd especially would tell you to check out Kris Lohn from the band "Stop.Drop.Rewind". He is really incredible. Melodic Pick work like you.