Mostly its space need to store it laying down. If laying one down can bend it, how would it ever hold up in an engine? I tried to break a camshaft once, took it out in the street and me my buddy kept throwing as high as we could, it might have bent it slightly, but it wouldn't break, we had to set it on a couple 2x4's and hit it with a sled hammer to break it in half. I am willing to bet a crankshaft would take a fair amount of work to bend or break one.
