I agree that Free and Open Source Software should be an important part of the FIRST universe. It fits.
That said, they are probably leery of turning off their current corporate sponsors. They really should not be. Any company that is not willing to play nice with other systems should be shunned. But they probably are.
Anyhow, running mcc18 under wine has not given us any major problems. It is certainly better than mplab on windows.
Maybe a better approach to getting FOSS in to FIRST would be to help them out. We could send out copies of The Open CD to all the teams:
http://www.theopencd.org/
That could make a great intro to Free.