It's hardly a waste of time to install pre-loads if you bought them, or want them digitally. Network traffic on release is terrible and that's the entire point of downloading them NOW and only needing a small update on release vs downloading 3.7 GB on a clogged server.
Yeah if a leak pops up and people install it, the pre-load was a waste of time but that isn't the case for every single person waiting. Stop assuming everyone who wants a pre-load thinks they can play early; some people just don't want to bottleneck on release.