There are some advantages to joining GNU: Publicity, which means more contributors Credibility, which may get MB manufacturers to evaluate the code sooner
On the other hand, RMS is petty about semantics. I think that not being allowed to use the term "open source" is silly. And then there's the restriction about "GNU/Linux" vs "Linux" which presents special problems for the OpenBIOS project becase the BIOS software is generally concerned with the kernel rather than with the whole OS. RMS might not be too pleased about us calling Linux "Linux" even though we really only mean the kernel, in cases where we *could* mean the OS.
I'm not opposed to joining GNU, but doing so will entail putting up with RMS's politics and rants.
M