Well, amps usually have heat problems when being run too hard / having the limiter threshold set to soft. Some do a better job than others of saving themselves, but, its not fair to compare amplifiers that costs twice as much or more to a budget amplifier. Crown XTi's and Macrotechs have good thermal protection, the QSCs and Crests are excellent at that. These also do a better job of saving the speaker (rapid/ramping gain protection, etc.) But they also cost more, so, *shrug*
As far as no bass cabs needing more than 1000-watts, both places I play every week require more than 1000-watt amplfiers for the bass section. The Meyers do, the Bag Ends do. Like you said though, that's spread over multiple (2 or 4) drivers.
Some of the new d'n'b and dubstep soundsystems are using drivers with high power handling the the ported low end units before crossing over to horns for the +40Hz bass. But, I digress.
