I think he's saying we remember folks who make large humanitarian or health contributions to society for longer because it's more relevant to more people for longer than products we consume. We remember some industrialists because they so far outshone their contemporaries and had an effect for more generations. With the speed that technology now improves that seems less and less likely to happen in todays cycle without a major fundamental breakthrough in physics but health related discoveries continue to remain relevant because humans don't change that fast physically. If Gates cures malaria (or rather people Gates has funded) he's probably correct in that he will be remembered longer and in a positive light.
That said the use of the word "revere" is a bit of poetic license on the part of the author of the original article. Gladwell actually claimed the 3rd world would revere him and raise statues to him for curing malaria but even that is silly in my opinion. I mean where are the statues of Jonas Salk (and I don't mean one sitting in his home town or at a university, I mean in all the various places polio was a problem)? I think Gates end up in text books and be remembered longer than Jobs as the driving force that found a cure but it will be in books and schools that his name is mentioned not in the streets like Gladwell predicts. All of this of course is moot if his folks don't find a cure.