The issue that authors of ancient software like his seem to have is that they might miss out on some royalties if someone uses it in a commercial way.
Others just don't want anyone to use it without their permission. Personally I don'y get that with something as obsolete as this, and its a shame if it just sits on your hard drive.
Try and see if you can contact him, and if not put it on aminet anyway with a readme explaining the situation.