Presumably, if you're going to need the level of access provided by this program, you're probably building something that makes some amount of money. That would make purchasing a paid plan worthwhile, even if all your repos are public.
Well, I don't see why Travis-CI, for example, would have to go on a paid plan to be part of the program. They are first class users of the GitHub APIs but it make no sense to be on a paid plan for them.
