I agree that interviews are probably not the ideal solution for selecting a medical school class. As you said, an hour or two is not really sufficient time to get to know a person, and it certainly is an unrealistic expectation to determine someone's suitability to enter medicine on the basis of a single meeting. However, what alternatives are there?
I prefer the interview as the final selection process over the use of marks and grade point averages. High marks don't really correlate to good clinical competance. Reference letters are clearly not the best way to discriminate between applicants, as it extends an advantageous bias to people who have "connections" to professors and doctors. Also, it's really difficult sometimes to compare two applicants solely on the basis of their reference letters.
In the ideal world, I would like to see the admissions committees follow
each applicant around for a week, and really get to know each individual.
See how they react to a panhandler, or a long traffic lineup, or even what
they actually do in the hospital while volunteering! However, this is clearly
logistically impossible. By and large, I think our class is an excellent one.
There is little to no competition between class-mates, and we have a very
diverse, and well-rounded student body. Like you, I don't think interviews
are ideal, but I like them more as a selection criteria than some of the alternatives.