A couple of objections: 1) I don't see how it is the GPL's fault that the Open CASCADA license is GPL incompatible. The Open CASCADA license was created way af

A couple of objections: 1) I don't see how it is the GPL's fault that the Open CASCADA license is GPL incompatible. The Open CASCADA license was created way after the GPL, and so if they wanted to use their code with GPL code, they shouldn't have made a license that was GPL incompatible. If they thought it was compatible, but it turned out it wasn't, then maybe their legal team doesn't have the acumen to fully design their own license, and they should have used one of the existing known GPL-compatible licenses for their work. 2) The FSF has long anticipated potential incompatibilities between GPL versions, which is why its recommended to license your software under the GPL or any later version, and indeed such language is provided in the license by default. LibreCAD's original developers changed the license to make it GPLv2 only, intentionally breaking license compatibility with software licensed under future versions of the GPL. If these people did these actions by accident without realizing the ramifications then the GPL could be faulted for being confusing (despite the very comprehensive FAQ page provided by the FSF), but I don't see how it's GPL's fault when people go out of their way to be GPL incompatible, or incompatible with future versions of GPL.