Although I agree that USUHS is easier to get into than a lot of other schools, I don't think that many consider it a last resort. Some people I know would never apply there, and others have it as their top choice. I think it's kind of like the DO thing - it IS a "last resort" for some, but many actually want to go there!
To answer the original question, I can only use my own personal reasoning. I am really interested in USUHS for several reasons, aside from the $. In fact, the $ isn't even my main concern.
1. Awesome medical training - you get an additional 700 hours of emergency medicine training, which includes an entire month of field combat medicine.
2. Really cool rotations where you get a chance to work with NASA, the CDC, the doctors at the White House, etc. You also have the opprotunity to get certified/work as a flight surgeon, or diving medince, etc.
3. After you graduate, you will have the opportunity (or burden, I suppose) to be stationed overseas and work in the kind of environment that many will never experience. Germany, Iraq, N. Korea, various African countries... not "fun" places to be, certainly, but I think that the experience of practicing somewhat "bare-bones" medicine would be rewarding.
4. My personal goal is to eventually volunteer full-time for Doctors Without Borders. In order to be effective with them, I want training - both in military defense tactics and in medicine. USUHS' motto is "good medicine in bad places" - that's what I want to do.
5. Mandatory physical fitness rocks. But that's just me
Well, that's my reasoning... PM me if you want to talk. I have my interview there in a few weeks, so i'll be able to give some details about my experience. I have also arranged to shadow a surgeon at Walter Reed the day after my interview (Sept. 25th), so I can post about that as well.
(oh, and btw, I have excellent stats - 3.83/33, so it's certainly NOT a last resort school... don't feel badly about doing military! Academia just has a grudge against it.)
- Quid