Taste is, well, a matter of taste, and humor is often the best way of making a point. Naturally some people will appreciate that humor less than others.
As for your second remark, let me point out that stereotypes are quite often simply exaggerated manifestations of a fundamental truth. If the shoes of the fisherman fit...
A teenager may think letting gas in public is humor, too. Stereotypes may indeed contain a core of truth yet it is the guilt by association that makes stereotypical humor inherently unloving and a cheap shot. [Note I didn't say 'Teenagers think letting gas in public is humor.' which would be a stereotype and unfair.]
Take some Bean-O.