There are techniques to avoid shadows in many cases - leaving very few exceptions - yet from the baying of the few anyone would think the 5DIII had a crippled DR system and totally unable to produce a good images.
I don't think it's "baying". This is a camera discussion forum, and these camera's aren't cheap. It's unreasonable and a bit naive to think that Canon's latest FF camera won't be compared to its chief competitor.
Why should you compare the D800 with the 5D3 - apples and oranges - definitely not its chief competitor
If the d800 is not the 5D3's primary competitor - then what body is?
D700 Mk II. 
But seriously, EVERY camera is a competitor. People will decide between 5d3 and a 7d, or a rebel. The 5d3 might lose out due to price. The D700 and 5d2 are competitors. But I would say yea, the d800 is the primary competitor, if only because that is what people are comparing it to. People who are in the market for a $3000 FF camera will look at the 5d3 and d800 and decide between them. that makes them competitors! So yea, they are all apples.
same price range doesn't immediately make it so. If strawberries are $4.99 a lb, and asparagus is 4.99 lb, does that mean both are the same?
Yeah, same price range. But they are two different beasts. If you primarily shoot landscapes and aren't bound by investments in lenses or overall budget/earnings the d800 is the way to go. If you are more of an all purpose shooter, the mk3 has many advantages. And while its not everyones cup of tea, if you shoot events and weddings and landscapes and are using canon systems, me thinks investing in ND and Grad filters would be a good work around to get more DR ---or shoot HDR...its not the best solution, but unless your making most of your income shooting landscapes I'd say switching systems is a frivolous investment...
(note I did not ad architectural work to this mix only because even with the DR of the d800, the canon Tilt shift lenses are much better than what nikon offers...)