Re: Why do guys pound on their basses??
Seriously, this is like a pick vs. fingers discussion, except even more pointless. There might be a showy-anger aspect to some of it, but to assume all of it is rage-related us just stupid.
If you pound on your bass, whether with your fist or your hip, you can get a thunder-like rumble -- or, as others have mentioned, if you do it rhythmically, it can have a percussive effect.
If you don't want your bass to make those sounds, then don't pound your bass. But don't accuse everyone who does it of supporting or condoning ragey adolescence.