You could say the same about the GPL - the practical effect is almost never to make a company release their previously-proprietary source code, the practical effect is to make companies not use it in the first place. Which is fine, as long as it's clear what the rules are, and the rules seem clear enough to me.
I don't think this is correct. It definitely seems like code that would otherwise be proprietary does end up being open sourced in the case of the Linux kernel with certain drivers.