I am sure that part of the reason that they are asking is because not only do they want to know about your desire to become a great physician, but they also want to have a group of people who are dedicated to the osteopathic philosophy. Although all the schools I applied to were osteopathic, I was still heavily questioned on the Osteopathic Principles, Wether or not I believed in OMM, the History of Osteopathic Medicine, and also my individual dedication to THEIR school.
Some questions included:
If you get accepted to more than one school, how do we know that you are going to choose us? What can we do to convince you? Why osteopathic medicine? A brief history of Osteopathic Medicine from its origination? Do you know specific dates? What examples of OMM have you seen/read about? Etc.
In the end, I think having integrity is very a important trait for any medical practitioner. I think that it is only ethical to answer ALL the questions to the best of your ability. Regardless, you made the decision to apply to both schools --so you must already have a good answer to they "why both" questions, as it is inevitable that they will be asked.
I do wonder why you would apply to SO many allo schools and only 2 osteo schools...I hate hearing people use osteopathic medicine as a backup when there are many qualified applicants who truely believe in our philosophy. If someone is that STRONG of an applicant, why would they apply to 2 dozen allopathic schools...and on the same line, if this applicant is strong and apparently wants/prefers allopathic, why apply to any osteopathic at all?