I think sek's post was more along the lines of "but what has he done for me lately?"
Right now, for every piece of open software that has enabled all kinds of world-changing good things, there's a dozen situations where open software is not a viable solution when compared to the closed alternatives for a wide variety of reasons, unless you're explicitly choosing to use only open software as a show of support for an ideological cause. What frustrates me about Stallman is that he spends his time lecturing people about why they're bad people for not using open software, instead of actively working to make open software a more appealing solution more of the time.
Have you ever listened to his talks? I have read a bunch of what he has written (mostly transcripts of talks) and did not get that impression. His main point is not that you are a "bad person" for using proprietary software--rather, it's more like you are the victim. Now, he does believe you should not use proprietary software, but because it's abusive and takes away your rights. Finally, I could see getting the impression that people publishing proprietary software are "bad", but that's a different story altogether.
Also, we're mostly developers here. Barring a few fields (things like .NET and iOS), free software is the best option for development. So while an artist using exclusively free software may be making a sacrifice, I have actually been much more productive on Linux/Emacs than I ever was on OS X or Windows. It's really a win-win situation.
Right now, for every piece of open software that has enabled all kinds of world-changing good things, there's a dozen situations where open software is not a viable solution when compared to the closed alternatives for a wide variety of reasons, unless you're explicitly choosing to use only open software as a show of support for an ideological cause. What frustrates me about Stallman is that he spends his time lecturing people about why they're bad people for not using open software, instead of actively working to make open software a more appealing solution more of the time.