Maybe it makes them uncomfortable and that's how they respond to it. Hell, its how I deal with discomfort. Course, they may just think the scenes YOU feel are powerful and emotional are trying too hard to the point of hilarity. What is the height of drama for one is narm for another. Course, if they were being loud and obnoxious, then that's a definite breach of theater etiquette.
Its kinda like how I find the songs on the radio about how this guy's girl left him to be irritating, whiny, and overall pathetic when you may well find them powerful and moving.