I just posted a comment there. I thought Glynn Moody was pretty strong FLOSS
advocate, but I dunno. He seems there to be totally all about GitHub, which
is proprietary.
I think the one problem is incompatibility. People need to use GPL compatible
licenses and just stop using the others because compatibility is a problem,
and yes, that means giving up the particular details you want so that you
instead are compatible. But then we're free anyway.
But yes, public domain is still free, but the question is whether it is
sustainable and robust.
