Re: Possible solution to different licencing...
Stealing is taking with intent to deprive the owner of it and without the owner's permission. Basing a commercial product on a permissive licensed one in no way deprives the world of the original version. I don't know about current windows but earlier versions used, and, in keeping with the licence, acknowledged they used, the BSD networking stack. That in no way prevented the same stack being used in other OSs.
If someone contributes to a permissive project they presumably do that in full knowledge of the possibility of someone basing a commercial product with it so the commercial product has the contributors' consent. The commercial product might be feeding back changes to the product. It might even fund the entire product.
On neither basis can the accusation of stealing stick. The only difference is that the permissive project can be shared in binary without any obligation to provide source code. Even then there's only a real difference if the commercial version has made changes that aren't fed back. And what's at issue here is one project forking a permissive project and making changes that can't be fed back due to the difference in licensing terms. If you want to consider a commercial closed version as stealing from the original project then you must surely apply the same label to the fork under the more restrictive licence.
From the PoV of the original project it's just sharing, as the licence facilitates but don't you think it just a little ill-mannered, to put it no stronger, to take the freely shared code from an original project, ensure that your changes can't be shared back and then claim some sort of moral high ground over the project from which you've taken it?