I’ve played in games where the host doesn’t play at all (admittedly those have all been raked games), and I’ve played in games where the host plays (both raked and unraked).
The only times I’ve experienced a host not playing at an unraked game is:
A) when there’s a waitlist so the host gives up their seat until there’s no longer a list
B) the host already lost heaps in the game
C) we’ve played for 20 hours or whatever and the host wants to sleep
D) hosting duties have pulled them away for a brief period of time (running to the store, or preparing food or drinks, etc)
Personally I think it’s odd to be at a host’s place and they aren’t playing. If they couldn’t afford it or weren’t feeling well, we could reschedule or move the game to another person’s place. But I also wouldn’t NOT play at a buddy’s game if he wasn’t playing. If the host has a great poker set up and just wants to be around the action, I don’t really see a problem with it.
For me the issue is much more the “one buy-in and I’m done” mentality. I think that’s really poor etiquette and almost feels like a shot-taker or sore loser. Not only does it leave the game shorter handed, but it also is a weird mentality for the rest of the table. They know if Jimmy busts then he’s out and they’re down a player, and if the game is super friendly, then people might pull punches because they don’t want to be the one responsible for Jimmy sitting out.
I can say that if I knew the host would always be one and done, I’d rarely ever play there.