That's exactly the point and it's happened many times now. OpenOffice got converted to a non-libre license so it was forked to LibreOffice and OpenOffice was left to rot. Audacity fucked around and now there's like 3 or 4 forks all competing there. That's the great thing about open source software, if companies or even individual maintainers do something that pisses off the user base enough, someone will come along and fork it. It's truly democratic as people vote with their feet, or downloads as the case may be.
I don't know honestly, I was never really an Audacity user in the first place. My limited googling though suggests there still isn't a strong consensus behind any of them yet though. It just sort of seems like you pick whichever one you like the name of the most.
Being licensed as free software (libre) just means users have the freedom to fork and continue without the copyright owner (to the degree permitted by the license).
The same bad incentives still exist but they are mitigated when devs know competition can sprout out of their bad actions.