The prevailing wisdom (coming straight from the mouth of the likes of LizzyM) is that undergrad institution has little more influence on admissions than perhaps the role of being a tiebreaker between two applicants who are otherwise similarly qualified. Now perhaps going to an Ivy will put you in a position to get involved in truly meaningful research, plug into the top levels of certain national organizations, or get you a rec letter from someone extremely recognizable, and maybe someone who went to an Ivy might be more likely to excel at the MCAT, but in-and-of-itself, I don't think the Ivy name carries a whole lot of weight.
And seriously, anyone still arguing with the OP over whether or not numbers are important in making a good doctor clearly isn't reading his statements, as he's not sayingthat; what he's saying is they are important in med school
admissions, which is clearly true, especially at top-tier schools if, for whatever reason, you have decided that you want to go to one of those. Also please note that nowhere has he made the claim that going to one of those schools is necessarily going to magically make you a better doctor either.
I think that once you're applying for one of the top schools, all they're looking for is a certain base level of competency being expressed by your numbers in order for them to at least consider you; a 30/3.6 sounds about right to me. From there, you're going to need SOMETHING that really sets you apart from the other applicants beyond the usual laundry list of pre-med activities. Maybe for one applicant, they're just a total academic superstar (3.98/39); maybe for another, they did 4 years of research and got several pubs; for another, perhaps they spent all of their summers abroad doing clinical work; another maybe started a health program for underserved patients in their area; and maybe another was an Olympic swimmer, or had some other crazy, unique life-experience. Clearly, the lower your stats are, the more incredible that "something" must be in order to get an interview and ultimately get accepted, but as long as you've got some basement level of stats, they're not going to reject you out of hand; after all, even the top med schools (other than WashU) only have MCAT averages in the 34-35 range, so by definition half of their acceptances must go to people with a lower score.
Therefore, I think it's a gross oversimplification to try and point to any one thing as being "most important" at a "top school." Clearly, at any of those schools a certain level of generally good stats is to be expected, but then, EVERYONE at those top schools is exceptionally qualified. Given that all of their applicants are well qualified, there has to be something in your application that's going to pique the adcom's interest and make them want to meet you; from there, that "something" can be just about anything. Research might be the most common way that applicants try to distinguish themselves, but it's far from the only way.
At least, that's what I think. That is just my $0.02, as it's really just my best guess of maybe how this crazy process works