Quite likely they get damaged even before that, while they are on semi trucks (feeders). Assuming that loaders don't realize these are vulnerable to crush damage, they could get stacked on top of each other at the bottom of a loaded semi with moderately heavy stuff on top. Judging from boxed bikes I've seen, there is minimal or no padding, so this could easily result in damage. Not sure if it's official UPS policy, but it's
much less likely for a presumably-expensive TV to end up stacked like that.
Surveillance - that's what supervisors are for. Really though, you have 800-1000 packages to load into 3-4 cars over 3-5 hours. When you have 20 of these bikes arrive on the conveyor belt in a 30 minute window and nowhere to put them (since it's hours from shift end and you can't put them in the delivery truck yet), they get dealt with fast and not so gently. That could easily mean a 3-4 ft drop onto concrete, and a supervisor would be unlikely to care since they know the pressure to go fast. The official policy is "hand to surface" for every package, but in reality you have to work at a pace where this is impractical - so it's ignored apart from egregious abuse of packages.
edit: as for discussion elsewhere here about proper packaging, here's FedEx guidelines/testing: http://www.fedex.com/us/services/pdf/PKG_Testing_Under150Lbs...
Some of the criteria, such as dropping the package 10x from a 30" height, might seem absurd if you haven't seen how the sausage is made. It really isn't.