Monster trucks for for mud bogging & arena shows. They're generally not designed to be rock climbers, thou they share a number of design principals & parts with rock climbers. They crush cars, pull weight boxes, jump dirt ramps & defy logic through sheer power. It's the American way. ;)...
The sound was already "pure novelty", get to an event early and you'll discover most of the trucks are actually pretty quiet running. They change something before the show, that makes them insanely loud. Probably open headers & some other tricks.
This serious?! The a global recession is to blame for why this generation has turned into the longest lasting generation since the Nintendo debuted the Famicom/NES. And it's funny that you'd be bitching about it, because last generation everyone was bitching about Microsoft unleashing the 360...