You would be an idiot to upload something onto the internet that is copyright and has your user info still in the files.
Applying these 'no re-up' rules just make HDBits worse than it could be without the rule, because its restricting competition. It's is one of the standard 'lazy' ways of try to force a monopoly on a market, or to keep your product on top without productive innovation.
I'm glad you brought up What.cd, but not sure why you bothered to mention the much inferior site Waffles.fm. What.cd is the one torrent site I've noticed to use innovation and not these lazy tactics to get where they are today (arguably best music source, arguably most successful private tracker).
Well it happens and thats why the rules are there.
I don't see how it limits innovation either. I would argue the opposite point really since if other sites actually wanted to compete or release original content they would have to start buying original material also which would be great. Some sites even do this like CHDBits, TorrentGUI and some other HD torrent trackers which is fucking awesome and proves your theory wrong. Competition drives innovation and a monopoly in something like HD content is never good, but the people can't just take shit and put it someplace else because that accomplishes nothing. If they bought all the stuff and added to the content available on the web then they would actually be doing something productive.