Frankly, I think everybody involved needs to act like they give a fuck how the whole thing sounds. In any reasonable sized
venue the soundguy's job is to: a) make sure the PA is installed and working and 2)
reinforce the sound of things that need it.
A 100W amp doesn't need it. Until the room starts to get really big, a decent acoustic drum kit doesn't really need it. These things are specifically designed to "hold their own" in decent sized venues. I wouldn't bother to mic Greg's amp unless he got an attitude about it, and even then there's no point actually cracking the fader.
But there are hacks and assholes in every aspect of it. Whether its the egomaniac who knows better than anyone else, or the clueless fuck who just wants to rock, or the bored dinosaur who's just there for free drinks and maybe a chance to get laid. You'll find them on the stage, behind the mixing desk, behind the bar, and all over in the crowd. Personally I take it seriously but not too seriously in whatever capacity I find myself. I try to foster the idea that we're all part of a team working to provide a singular experience to our audience. It's nice when we also make money.
If it was all up to me, every
venue would have a nice set of drum triggers, a number of DI drops, and licensed copies something like
EZDrummer and
PodFarm. The bands could design their personal backlines on
the venue's website. Every aspect of the production would be smoother and easier and with a higher chance of ultimate success. It ain't gonna happen any time soon...