The second is true, but it is also letting your customers have root (as the OP said.) It's control through the threat of ending a relationship, which Redhat is

The second is true, but it is also letting your customers have root (as the OP said.) It's control through the threat of ending a relationship, which Redhat is also trying now. You can't really say that it's allowed for in the GPL (there's no text in the GPL that says that it is allowed), it's just something that the GPL does not cover.