Couldn't agree with you more!
I completely understand letting out a little "verbal steam" when you are pushing for that last rep or two, or when maxing out and need everything you've got, but my personal "pet peeve" in the gym are these couple of guys who scream over every damn little thing they do.
Come on, during a 15 rep set, there is NO REASON to scream during all 15 reps. If you need to scream during the first rep of a 15 rep set, there is something seriously wrong with your mental approach to lifting weights, or your need to attract attention.
Again, don't get me wrong, when I see some guy squatting a pile of plates for his last working set, and he grunts out the last two or three, I definately respect his intensity - many miss out on that important part of a great workout. But seriously, no one wants to hear you scream during all 15 reps of your massive 30 lb. dumbell curls!