The initial author made no mention of the word "top" in reference to research heavy schools, you added that on your own.
But it sounds like you know something I didn't, you should post a link to that survey or at least give the name of it. Why don't you look at the list of the top 20 NIH funded medical schools,
http://www.brimr.org/NIH_Awards/2008/NIH_Awards_2008.htm, and see if the # of those self reporting research reaches the "essential" threshold in the survey you mentioned before?
Table: MSAR
Even better idea, than listing the top. Of schools ranked 60-70 out of 127 (note: this is because i'm too lazy to do that many schools and the next obvious argument is, what about not "top" schools)
UArizona / 81 // 90 /// 69
UVermont / 82 // 88 /// 77
Wayne State 81 // 90 /// 71
Brown / 78 // 64 /// 60
UConn / 87 // 84 /// 70
UMDNJ-NJMS / 78 // 84 /// 64
Penn State / 87 // 86 /// 73
UKansas / 59 // 78 /// 72
UMDNJ-RWJMS / 81 // 90 /// 66
New Mexico / 72 // 90 /// 77
AVERAGE / 78.6 // 80.7 /// 69.9
So research is just about as important as health related work and significantly more important than community service.
I realize this is a logical issue, since we don't know how many candidates applied/rejected with significant research vs. significant medical work vs. significant community service, but you also have no basis for arguing that research is non-essential (unless you are also prepared to argue that medical work and community service is non-essential).
Admittedly the OP does not say "top", but the person you were responding to said research-heavy schools.