Where golf tournaments are played is usually a question of money, not architecture.
For the USGA, "tradition" is a big factor as well. The importance of the U.S. Open is in part a circular argument, from "it's played on the greatest courses," to the greatest courses being defined as those that have hosted multiple U.S. Opens.
But behind the scenes, there is a lot of money being thrown around. Many of these host clubs have just spent EIGHT FIGURES renovating their courses to cement their reputation as championship-worthy . . . for which the USGA and PGA did not pay one penny. Members did, by voting to spend each other's money. By contrast, I am trying to think of a private developer who would spend $$$$$ for climate-controlled greens and concrete lined bunkers and all the bells and whistles, and not many come to mind.