Third, who the heck is 'the entire Canon community'? I can only assume you're referring to the tiny minority of people here bitching about Canon's 'terribly low DR' and 'horrible, shot-destroying pattern noise.' The 'Canon community' and in fact, the dSLR-buying community at large seems to be quite pleased with the 5DIII, and with Canon in general. Have a look at Amazon.com's Top Rated dSLRs (note - top rated by customer reviews, not top selling, although Canon owns the top of that list, too). The 5DIII tops the Top Rated list, and Canon holds the entire top 15. Then we see Sony...but where's Nikon? One Nikon camera in the top 20, a total of 5 in the top 40. And the D800? Based on customer feedback, it's not even in the Top 100 at all (the D4 and D700 are in the top 50, but only barely). So I'd have to say WTF to your claim that 'the entire Canon community' is dissatisfied with the 5DIII. A 'community' of about ten (excuse me, now about nine) naysayers here such as yourself, perhaps.
I'd say that the issue your dealing with is that the "Megapixel/DR" community tends to be the most vocal on the net. Partly I'd say because the serious landscape/macro market naturally tends to be a bit more "techy" and so involved in gear forums but mostly because these elements obviously count for more with the for the want of a better word "measurebators".
On this forum I'v no doubt most of those after more Megapixels/DR are in the first group but on the net as a whole I think the vast majority are in the latter. These are elements that can be tested to your hearts content shooting brick walls (or more likely looking at other peoples shots of brock walls for cameras you'll never own) where as the benefits of improved AF, FPS, weather sealing etc will be felt more when actually using a camera to take photos out in the world
Its not as if there isnt discontent on the Nikon side aswell though, head over to any Nikon forum and you'll find people bemoaning a lack of a true sucessor to the D700.