Paul,
I resemble those remarks. I felt I was falling into a pattern. And while many here bemoan the use of "formula", I found that if I kept studying, and developed a hip pocket list of ideas I wanted to use in appropriate places, that I could get MORE variety, not less. Of course, the land does have to speak to you, but it doesn't have a lot to say sometimes. And when I worked in Asia, perhaps I didn't get the translation! Anyone who thinks it's better to start routing a golf course and designing it's features without some ideas from experience about what the final product might be is, shall we say, being a bit romantic! Would that person go to the airport and board any plane without regard to where it was going?
So, like it or not, from experience and study, I have developed about 2 dozen favorite strategic tee shot patterns and rationale for using them in certain winds, hole lengths, etc. (so far - I keep adding) and figure my courses should not have more than one of each, unless perhaps one favors hooks, the other fades. I also have a list of historically inspired greens, etc. like fortress, punch bowl, valley of sin, etc. etc. and a certain list of crtiria for bunker patterns, green contours, etc. which I work hard to incorporate. If I don't, then I find the natural tendency to repetitiveness starts to kick in. So, call me "Seth Junior", but it seems to be working, though.
Of course, the original question has turned to creativity in architecture, but I'll bet when you and I read it, we said "Hell, Yes!" - I've learned the technical side that keeps me from making mistakes. This site, as Tim Jackson said, doesn't generally recognize what a large part of the business that is.
In the case of Frank Lloyd God, I hear that while his creative side kept evolving, his roofs leaked from beginning of career until end, meaning his experience didn't necessarily make him a better architect in that regard. Of course, he had the benefit of Taliesin, where he seemed to continually bring in young students for a song to get a chance to work with him. It's possible that he didn't keep making the same mistake, but that it was a new mistake for that year's crop of draftsmen.