I can't think of a single photograph generally regarded as "great" in which technical perfection, whatever that means, was an issue of any kind -- either the presence or the lack of it. When it's present, it's taken for granted. When it's not, it's unnecessary. Technical perfection used to be hard to get because everything was done manually and at slow speeds, and then had to go (blindly) through a series of chemical baths in which many things could go wrong. Therefore, most images had some imperfection, but it didn't keep them from being considered "great." If you're a collector, one of the one-going discussions that takes place is whether or not a print of a given image is a "good" one. Ansel Adams printed several hundred and maybe more copies of Moonrise, in several different sizes, and the quality varies (although it's usually extremely high) -- but the image itself is considered by most collectors to be one of the greats; in other words, the quality of the image exists separately from the technical perfection of the print. Capa's Normandy landing photos were damaged in the lab (he didn't process them) but are still considered great, partly because the damage to the photos seemed to enhance the terror and violence of the moment. Paul Caponigro's "Running White Deer" has sharp trees and blurred white deer; if he'd chosen another technique, he could have had blurred trees and sharp white deer; if he'd chosen another technique, they both might have been sharp. So which is technical perfection? Henri Cartier-Bresson's "Behind the Gare St. Lazare" (man jumping a puddle) is actually a little fuzzy...so what?
I can even think of a couple of famous photos that were partially faked -- in one, a figure was eliminated because of a conflict with another figure (but the photographer neglected to remove the shadow of the missing figure) and in another, by O. Winston Link, his famous drive-in shot with the plane on the drive-in screen, the image on the screen was almost certainly a cut-and-paste job.
I personally don't think technical perfection is very hard to get anymore -- if you can afford a tripod and good equipment, and are shooting landscapes, your camera can probably take something close to technically perfect photographs with very little input on your part. Most photo-journalists in fast-breaking situations will put their camera on auto-everything and concentrate on the action, letting the camera take care of exposure and focus; you need to know a few more things, of course, but if somebody seriously applied himself, I doubt that it would take more than a month or so of parttime work to get to the place where 95%+ of your landscape photographs would meet the standard of "technically perfect."
Whether or not they were interesting is a whole different issue; that's one reason why so many issues of National Geographic are so forgettable.