Apart from attacking DxO Labs, Lloyd Chambers sent back several (iirc five) 70-200 IS Mark II lenses before he received one that was sharp over the field. This suggests that there's at least some possibility of a quality control problem.
Having wasted money subscribing to Lloyd Chambers site last year, all I can say is he's either very unlucky or he just doesn't like Canon or Nikon lenses. There's always something wrong with them, be it asymmetry, CA, mis-focus etc etc. Yet put a Zeiss in his hand and the world is good. Funny, apart from Zeiss's ability to produce a unique rendering style, their inability to control lens aberrations (whereas Canon and Nikon are quite successful in this regard) hardly gets a mention!
And yes, DxO's data is crap in my eyes.