On the flip side I've seen people who change their characters basically once a month then they act shocked when there is a feeling of lack of investment because other players don't want to spend their time trying to build something with a character that will vanish on a whim. They also get passive aggressive because storytellers won't give their characters roles that require responsibility and long-term investment ect.
The other one, and pathfinder grogs are the worst at this (or at least the ones I've encountered) is they want to try out the new Reddit Approved game breaking build.
(Author's note: anyone playing pathfinder 1e after 2016 is a grog. Sorry not sorry)
I had a PF grog who would build characters hyperfocused for the the situation they were in, and then as soon as that situation changed, would "get bored" and ask to roll a new one. And as you said, would get a little grumpy when after his 3rd character I didn't bother making him any plothooks and everyone else was doing shit with their contacts & character arcs.
He eventually chimped and soft-ragequit (tl;dr - there was a gelatinous cube with 3 skeletons inside it so the party sees three hovering skeletons advancing on them in formation; it was dark and the lvl 4 party failed their perception checks to notice the cube, they attempted a arcana check and found no magic. Grognard took his character and charged around, trying to get into the gap by the skeletons, only to find himself Cube'd becasue he charged right into it (I gave him saving throw to pull back at the last minute. The dice wanted him in the cube), and being MOST displeased about that. He more or less refused to participate for the rest of the session and then sent an email bailing on the game, after I texted him to see how he was doing.
which saved me the trouble because dude was either going to talk about what was up his ass or get booted)
But in between, we were not playing pathfinder, he kept trying to do Pathfinder stuff; assuming AoO happened on pathfinder conditions, do pathfinder dirty tricks, etc.
Which normally I'm flexible about that sort of thing and will say "You can't do X, but lets say you did Y which is like game mechanic Z, so you'll roll this sort thing" but because he and another pathfinder grog refused to parse non-pathfinder rules, I was holding to RAW until they de-paizzo'd their brains, which they never did.