To me, as a bassist (and these remarks pertain primarily to jazz, but I think do hold true for music in general), when drummers are playing too loud it's not because of a technical problem or an equipment problem, it's because they aren't really listening to what's going on. They aren't playing with ME (and the rest of the band), they are playing to some agenda or with some band in their head. Because if you are LISTENING to the band you are going to play at a level that you can HEAR the band.
Granted, when playing in a jazz trio there's little excuse for over playing (volume wise.) This is mainly because the general stage volume is such that the drummer can actually hear him/herself easily amongst the rest of the musicians.
More often than not, this is NOT what's happening in common pop/rock/(insert electrified music genre here) type situations. Most drummers find themselves surronded by stacks of screaming Marshalls or towering, thunderous Ampegs set to "11."
Stage volume is normally very high and unless the production is large and you have a full range monitoring system aimed right at your head, you must play loud just to hear yourself.
It's virtually impossible to play quietly when you're being driven into nonexistence volume wise.
If you cant hear yourself, you cant play.
