Its a matter of degrees. I think every major golf market can stand a good replica course, either of Scottish or Early American or Golden Age american classics, for reasons mentioned. But, I think they need just one, of course. So, if 50-100 of 15,000 US courses is a Scottish replica, Tour replica, or whatever, whats the big whup to you?
As to the gca taking a fee to copy his own copies, there would still be the time to fit it to the topo at hand, not to mention the specs and construction supervision.