What's wrong with proprietary software? Also, I'm not fond of his philosophy when it comes to programming. Not minimalist enough. Everything is bloated.
People have this wacky idea that you have to have evil, proprietary, spying, patent-ridden programs, or you have to have GNU-brand free software.
Richard Stallman wasn't the first person to make free/open source software, and there are other camps who don't like the proprietary stuff either (OpenBSD and Linus Torvalds are good examples). You can have both, or at the very least not force people to take sides.
Stallman's rhetoric works really well though, especially on young students, because people like the idea they're fighting for freedom and whatnot. I have personally known dozens of people who fight for their rights by using GNU but who have never written a line of code in their life.