Martin -
It is interesting, isn't it?
It wasn't at all clear then. But it is now. As night follows day, the same mindset that would build ranch-style clubhouses in the 50's and 60's would also (a) "modernize" a lot of Golden Age architecture and/or (b) construct countless truly awful new courses.
I am old enough, however, to remember when that look seemed really, really cool. In fact, the house I grew up in looks much like one of your photos.
Bob