I guess most companies that buy from Hwaci are more concerned about long-term support than about this public domain thingy, and "yes, we obtained a license" is just another box they need to check. $6K to check a box is pocket change to these companies anyway.

Besides, most countries in the developed world have some notion of giving away one's copyright (not moral rights, which can't be given away) so it might not be as much of a problem.