> Sharing code is no longer cool if people have to share back. Or at least so it seems.
There are plenty of licenses which require/encourage that. The problem with GPL is that everything that touches the GPL code has to become GPL or compatible.
Adobe for example will never put this in Photoshop, or Microsoft in Internet Explorer, as they do not want to GPL their software. Net result is no wide support for this image format, which is a net loss compared to a e.g. LGPL/MPL scenario where companies could do that but still would have to contribute to the library if they made any changes/improvements.