[NoGravitas]

The Peer Production License and its relatives are pretty good generally. The problem is always license compatibility. One of the benefits of Open Source licensing being kind of standardized has been composability. There's been a pretty clear gradient of "restrictiveness" of licenses, so when you mix software together, you just have to use the most restrictive license of your dependencies (or one that is more restrictive). Copyfarleft licenses are a good thing, but they make the restrictiveness dimension diverge in different ways, so you can't necessarily mix them with each other, or with the GPL (say).