I think it is much more difficult to control a distributed mass of web-broadcasters and that is what shifted the balance to making them pay-to-play. When you can't move the payola around effectively to promote where your profits will come from there is no benefit to the "promotion" argument. The lack of control and therefore requirement to pay for web-casters accidently came back to bite radio broadcasters to maintain the illusion of being "fair." Of course, taken with a grain of salt ;)
Think they may be suffering symptoms of: The Stanford Prison Experiment? Here are some: Videos. Basically give 'em power and they get stupid and abuse it. Same pattern happens all over, as in Iraq and Abu Ghraib. So, I guess they need to be spanked by a grown-up.
It's called "plagiarized" in this context because Disney took the idea, locked it up (which is ok for a limited time) but then abused copyright law to keep his additions from ever returning to the public domain. Effectively "stealing" it.