Why bother? Las Vegas is within driving distance of So Cal, so they get that market anyway, but in Vegas the venues and hotels are cheaper, and there's other stuff to do.
Because I can't stand Vegas. It is a desert, it is usually far too hot, and you see some of the most pathetic people there. If it were here in LA, I might actually go to the Olympia one year. However, it seems that the tickets are way over-priced, so I probably wouldn't go anyway