There are other services out there streaming content that probably don't pay anything and may be using safe harbour privileges for that reason.
I'm not exactly an expert in this area, but my gut feeling is that it would not be fair to say that because YouTube pays little to nothing to intellectual property owners, they're not abusing some sort of safe harbour privilege. YouTube is now in the business of promoting content to get users onto an ad-driven platform; they're selling advertising to bring users to it, as opposed to being a passive distribution mechanism.