I lump trappers and poisoners in the same boat.

I know where to get ingredients, but I also have a fair idea that it would be a pain to collect them because thief melee is terrible, and they know comparatively few weapons so they get tooled even worse.

Why would I want to play a horribly underpowered class that needs to spend ages prepping just to be competitive in PK?

I'd rather play a binder that has their skillset available without the drudgery.

It's very telling that to my knowledge not a single IMM has recently played a trapper or a poisoner. I think it's because they just aren't very much fun.