Unfortunately for soundcloud, aren't they killing their main userbase? DJ's mixing mainstream songs.
I thought the same thing at first, but the users that are linked to are all big, big names that get millions of plays on Soundcloud that will never get takedowns, whether they have clearances or not. It's more like saying "why are you hassling me for my $10 unpaid fine when you don't care about these corporations' $100,000 unpaid fines" than it is about narcing on the competition.
I learned that the hard way in 2001 when the IFPI went after my links (yes, only links) to then popular sites like mp3board.com and others - while the biggest news portal in the country had exactly the same links and weren't prosecuted at all.
It is possible that it was an "offer you can't refuse" type thing. I doubt they'd do it voluntarily.