Agree, the amount of people who license things as MIT is terrifying. There has been a couple of posts/rants on HN about this. A large company doesn't care about you, and licensing your code as MIT doesn't mean they're going to pay you. GPL actually gives you some teeth.
The argument is that those people were never going to pay you money anyway so don't cater to them. All you can do is try to make it seem like it is cheaper to pay you for a license exception than it is to reimplement, but some places will reimplement anyway.
