One other alternative would have been to release the framework into an open-source community project.
Sure. Let's just assume Grey would be more than happy to completely ditch a project he has been working on for 3-4 years for no good reason whatsoever.
Personally hope Grey got at least close to a six figure sum for this project.
if Mark were to sell BlitzMax to, say, PopCap under the same arrangement, it would basically leave your Blitz development at BFG dead in the water. Wouldn't you feel a little betrayed there considering the contributions you've made?
If it were the same terms of this sale, then all current owners of BMax would be free to continue to use the product as they do now. Even the forums would stay open.