Usually there's a reason for such actions -- a bullet on a resume or being seen helping out one's fellow man.
Why's Greg slumming with that fat unemployed single Latino mom? He's got a degree and a good job. Well, he's not over his divorce and he just wants to enjoy something light, fun and very sexual. He says he can talk her into anything. He'll get over her and move back up to someone more his level soon enough.
A. Make fun of them.
B. Make yourself feel better about your own life or give pity/gain experience slummin it to see what life is like out there for the unfortunates.
Bob went over the projects to rough it out and see what it was like to live a day in the life of someone who lives worse than ethiopians.
Jim: Hell yeah! I love knowing that there's plenty of trash out there to keep the burgers flippin'.