It isn’t punitive. When you raise a truck, the bumper is no longer even with all the other bumpers on the road. If someone rear-ends you, their car may travel under yours until your bumper hits something inside the other vehicle’s passenger area that causes it to stop. I don’t know all the ins and outs of insurance, but I think that modifying a vehicle in such a way that its systems that were originally meant to protect people in the event of a crash are now more likely to cause injury and death might open one up to liability beyond simple fault in an accident.