They are binary files, so you cannot create diffs between two versions. That is, the advantage of the openness of the source is void. I see your point. That is an aid for maintenance. At the same time, the Type 1 font contains all the information and can be converted automatically to the textual format. So it is a valid source format. Thus, I think these packages are valid and free as they are. However, distributing the ASCII source would be an improvement. So why not add that to your packages?
So after all, I don't think it's such a big deal if you distribute binary font files as long as they remain editable and convertable.
- Fabian