The trucks in question have outsized power for their size, it's part of their legitimate use as work vehicles. You get in these massive, comfortable vehicles and you accelerate, maybe not as fast as a sports car, but you're easily beating a Honda Civic and instead of a squeal from the transmission you hear a deep-throated roar from your engine.
Why are larger vehicles inherently more fun? A go-cart is fun. A double decker not so much (I would guess anyway).