i believe it. when you're bashing its usually in an open space. not a lot of solid objects to hit. the only time you're going to break is if you're jumping and crash.
racing on the other had is a torture test. you're in an enclosed area, pipes, walls, sometimes poles, turn marshals, and other cars to collide with. there are also more obstacle's, jumps and corners. the car is never has time to relax.
i can hit all my bash spots 50 times and not break anything (in fact i haven't broken a part in almost a year!). i haven't run on the track enough to have enough info to judge, but based off friends who regularly hit the track for test and tune nights, not a night goes by that one of them doesn't break something. (funny to, last time i was there one of my friends managed to case a jump which lead to a cartwheel and the motor in this SC10 hit the eject button. it just snapped both screws clean off)