[ashark]

Interesting. I find it hard to imagine that the reflected sound from the wall could be worse than the ear-against-tv-speaker-volume-at-full-tuned-to-static effect that ~2/3 of small venues I've been to end up with, but that does explain the motivation for it, at least.

[KeytarHero]

Well, in most cases the stage volume is already in so-loud-you-lose-clarity territory, so the clarity you gain from the sound guy turning up the mains a bit is worth the clarity you lose due to the extra volume. We're not talking massive increases in volume here.