griping

A really common instance of inconsiderate behavior is when someone knowingly deprecates a thing loved by the person they're talking to. There's a polite way to do it--"not my cup of tea," or something to that effect. Communicates the sentiment without being crass. But it seems like that kind of restraint is rare. People love expressing disgust.

Say you know your friend likes a movie. If you want to be a big jerk you might say that the movie is bad. Because the transitive message there is "you like bad movies." Or taken a logical step further, "your opinions have no value." Why do people do this? Best case scenario, they're just thoughtless. They've got some pent up aggression and it comes out like this because they don't pay attention to what they say. Best case scenario. Otherwise, they're intentionally belittling their friend and that speaks to a whole different kettle of deep dysfunction.