Assume this was said in jest. However, in reality, it's not true. I have no issues with a candidate who also wants to attend another SA (as well as USNA). My goal is to ensure a candidate ends up at the right/best SA for him/her. There is no benefit to anyone if someone attends USNA who really wants to be at USMA. Or the converse. So telling me that you are also interested in another SA will not cause me to ding you at all. I might actually talk longer so I can explain the benefits of USNA.One way to dramatically shorten the BGO interview is to say how much you look forward to attending college along the Hudson.
That said, if you have zero interest in attending USNA, don't waste your time or mine.