The FSF's definition of "Free Software" doesn't necessarily match the English language's definition of "free software". Since we're speaking English, I think it's reasonable to assume the latter meaning, like most reasonable people who haven't encountered the FSF would.

I really wish people would capitalize things like this. "This is not Free Software" would make the sentence unambiguous. You can't just go around redefining the English language willy nilly and expect people to play along.

Languages do evolve naturally but this isn't natural. This is an organization trying to influence the language to advance an agenda (though I believe it to be a worthy agenda, it's still an agenda).