> Why else would they have liberated what they have?
A lot of reasons really, and I can only speculate, but the most significant contributions to libre software gaming by far have been those by id Software. These contributions were made, as far as I can tell, because the engines were obsolete and it gave id Software a little street cred in the open source crowd, which was big at the time.
The other one I'm familiar with is The Ur-Quan Masters, which was probably given the source code release because it was about to become an abandonware obscurity and, fortunately, the original developers were able to get back the copyrights to it and scrounge up the 3DO source code. Under normal circumstances, not only would that release have been legally impossible, the source code would probably be completely lost anyway.
> what about all the free code developers and libre artists who might be motivated to fork both the trap and non-trap games, to create fully libre versions?
Absolutely do that if you are motivated to do so. It's just as good as developing a new libre game from scratch, and it's much easier in general.
> Again, we might be best to just agree to disagree about this and see what happens.
Sure thing.
