License vs Emblem?
I have pondered this question from time to time and occasionally posted thoughts on related discussion pages, etc. I have come close to abandoning the idea many times and going the emblem route but always end up leaving the proposal up for consideration with perhaps some minor change to incite discussion.
The most notable development since it was proposed is CC0 (see the FAQ. The CC0/public domain options are weak if the aim is to protect the commons and encourage contributions and participation (in free culture, libre knowledge, etc.).
The current form of the proposed Libre Puro License still seems sound to me and it is still a license I would use - though as a license I might prefer a stronger "libre share" - one which requires successive derived works to retain the freedoms (copy-left-like but not requiring necessarily the exact same license).
Given this "weakness", perhaps the "license" amounts to an emblem? Perhaps such an emblem would ultimately be more "powerful".
For now, I leave the proposed license up - it is always a fun discussion point for learners.
Comments on the emblem approach are welcome.