Ooo Comedy , why are you so funny??

I can't get out of my head the fact that we watch the Chapelle Show in class. It was awesome. I haven't seem that show in years and the fact that I watched it with a different state of mind made it a little more interesting. The Chapelle Show and others like the Roast of... or Always Sunny in Philadelphia are alls hows that pick on different races and cultures and its never bad because its funny. It may be offensive to some but no one really ever complains or the networks wouldn't let them air, I think. The Roast of... on Comedy Central is by far the worst show when it comes to making fun of others. Yes, they are making fun of themselves and yes it's hilarious, but why is it ok only when its funny? Is it because they're stating the obvious, or is it because those watching rather have someone else say what they have possibly thought. When I watch these kind of shows I laugh because I know it's just a show and no one ever really means it. Who said we can't laugh at each other without getting offended? Whats funny to me is that, my friends girlfriend hates anything to do with racism, she loves all and sees them as no different than the other, so she doesn't watch these kind of shows but she's the biggest UFC (Ultimate Fighter Championship). How can she, and I'm sure many others, watch people beating the crap out of each other for entertainment and not watch comedic shows that make us laugh at ourselves. I don't get it.