Seriously, why isn’t there?
You’ve probably heard the rumor that residents objected to the construction of a stop there out of fear that it would lead to an influx of riff-raff and other “undesirables.” But, according to Prof. Zachary Schrag, an assistant professor at George Mason, that’s not the underlying reason. Instead, he says that a Georgetown metro stop would cost too much (due to preservation efforts and proximity to the Potomac) and provide only limited benefits (Georgetown is not a big employment center and the commute from Virginia would be slowed with a stop there).
Interestingly enough, also according to Inside the DC Bubble, “the only station killed by local opposition was the Oklahoma Ave. station in Northeast. The largely African-American neighborhood wanted to remain quiet. The residents convinced the powers that be that the station was a bad idea.”