Do you really think Tillinghast's later work was much better? More refined, perhaps, but his first three significant courses were Shawnee, Somerset Hills and SFGC, which are all pretty darned good.
I'm reading a good book right now, The Black Swan, where the author ruminates about (among other things) how artists tend to become too safe over time and to start listening to their market instead of to their inner voice. Probably a good thing for me to read.