I could see that holding true among the general population, but among developers? What developer who's going to be browsing Github doesn't know what copyleft means?
There are more restrictions.
Yes and no. Even licenses like the Apache License do impose restrictions of sorts, and the whole "permissive" vs "restrictive" thing is hardly a binary proposition. It's a continuum... and that's not even considering that saying "restrictive" raise the issue of "restrictive for who?" Yes, arguably the GPL is more restrictive in terms of how a developer can interact with GPL'd code, but from an end-user perspective the GPL is "more free" in a sense.
All of that said, I get the point behind a simple binary "restrictive/permissive" flag, and I think most people would intuitively grok the general sense of it. I'm not opposed to it, but I think we could do better.
Hmmm... that raises an interesting point... does Github have any sort of notion of explicit support for DOAP[1] files? Encouraging people to use DOAP files might be a better answer anyway.
