And that's the crux there. It's not always malicious (I want to make a proprietary extension and sell it), sometimes it's a fact of the environment (I have to link this against a proprietary library in order to deploy to this hardware). Some will say "find a new environment that isn't developer-hostile", and others will say "find code that doesn't impose those restrictions." It's not black-and-white.
I have the greatest respect for RMS and the FSF. I compromise on my freedom as a developer all the time; I know that. But thanks to the ideals that RMS puts forth, I know that I'm compromising. I know what the risks are to using BSD instead of GPL, and so I weigh those risks.