No one in favor of the gondola has said that we should do it because it's cool. And the reason they bring up Portland is because the situation in Portland is similar where you've got a destination that doesn't link up too easily with an extension of the existing transit system.
And DC has far more options than just metro so it's not a "metro town." Even if I agree that we should build metro through Georgetown. Roosevelt island has a subway stop as well.
And if the study is crap then it'll be crap. But let's at least read it with a fair mind.