It's a myth that Georgetown residents vetoed the idea of a Metro stop. Among the many sites that make the case for debunking the claim:
https://georgetownmetropolitan.com/2011/01/24/all-you-need-to-know-about-the-georgetown-metro-stop/
Bottom line is that Metro itself wasn't interested because of the geography/topography and the lack of commuters going to Georgetown at the time.