I think part of Greer's problem is that he has a bit of a self-destructive streak; his anger issues are part of it, and so is the "I'll just eat this thing that might be toxic".
Edit: Whoops, Greer ate on the first trip, before they knew they were staying.
So, out of the eleven that were staying, they showed three or four definitely came back -- TJ, Scott, Chloe, and maybe Volker (he came back, but I don't remember if he was one of the eleven wanna-be-lost-colonists). So did anyone stay behind?
Besides Caine, who must have a doctorate in idiocy -- how many friendly alien races has humanity met in the Stargate universe, versus how many hostile ones?
"Whoever built this has to be nice, and capable of trans-galactic travel, so of course if we hang around they'll give us a ride home, and we'll of course be able to survive the sub-freezing winters until they get here, even though we have zero survival skills outside of Scott and TJ, the Air Force base personnel; what could go wrong? I've got faith!" Yeah, that's clever thinking.