I agree with the OP, it can be a bit of a bummer at times when you are around "those "particular kind of students. But to each their own. Just do whatever you can to relieve stress, let loose and have a little fun.
For example, we started a legit and fully functional Soccer Club at Nova, West Palm Beach satellite campus. Since we are missing out on a lot of the perks and amenities of the main campus in Davie, we have begun to be pro-active. Our Soccer Club has cool jerseys, practices every Friday, 20+ members, membership dues, SGA funded and played 2 real soccer matches with refs and all. Besides that, our class of about 50 in West Palm is pretty close and a lot of us hang out on weekends or whatever to relax.
For me, it's all about balance. I play guitar everyday to clear my head and in between long study sessions. Also, just generally being active on campus and involved with other like minded people, faculty, etc is always a plus. You're always gonna have those "debbie-downers" in your class and the ones that are super stressed and always studying/complaining. Sucks, but let them be.