While I agree with most of you that this waitlist for the interview is not just annoying but hurtful, I'm gonna play a little devil's advocate...
This school gets a ridiculous amount of applications, being one of the schools that get the greatest number of applications. With over 13,000 people applying for one institution, they cannot be limited to "great applicants" but "great applicants who REALLY want to be here" Imagine if you were on that committee..how do you choose one over another in terms of similar stats and comparable experiences? Answer: how strongly they feel about the institution, its mission, and will mesh with the class.
I wouldn't give up. If GW is really the school you want to attend with your whole heart, then tell them that. And tell them how well you'll fit in with the opportunities there, the community, and the rest of the class. But if GW is just another school to you, you are destined to go to the school that you ARE in love with.
Just my .02...don't mean to hurt anyone or cause issues by saying this. I hope it all finds you well.