I'm sure there are a handful of giant a-holes working at any of the package sending companies that do that, but it wasn't the norm when I worked at UPS in the 90's.
However, Kael's scenario is pretty much dead-on to what I experienced when I worked there. That's exactly how they teach you to unload trucks, and they bust your balls about getting them unloaded on time, so that's usually the only way to get done in a timely manner. Nobody I know ever smashed fragile packages on purpose, but nobody reads the packages when they yank one from the middle and make the wall come down. I don't know that any other package companies are any different, though.
At my local UPS, we'd handle over 12,000 packages an hour and maybe 5 or 6 a day would end up damaged, and they were always the flimsiest packed packages. So pack whatever you send to survive a 10-ft drop.