Adam,
Given travel and even digital photograpy, it is easier for designers to visit courses, if only virtually than ever. I gather the modern gca visits his projects far more than the old guys, and checks in even more often.
As far a budgets, they probably have always been tight in 90% of the cases. Maybe only 80% in the 20's and 90's. Your comment reminds me of my grandmother who used to say it got harder to get by every year. By her figuring, it would be impossible in another so many years, and yet we do manage to hang in somehow. Some things get cheaper and just as good, some corners get cut, and the Owner pays incrementally over the years but doesn't know it, etc.
Endless tweaking time would help the architecture of any course. It remains to be seen as to whether that would help the bottom line. Most often, it wouldn't, so it doesn't get done.
The disowning of courses by GCA's is probably pretty rare.