Didn't say it was Nvidia's fault (though the 100% reproducible crashes in newer drivers don't help). It's BioWare and EA's fault, for rushing the game and not giving it proper quality assurance testing. I'm sure AMD did nothing to help performance on Nvidia cards (why should they?), but there's no evidence of "features" in DAII that specifically play to AMD's strengths and Nvidia's weaknessess while providing no IQ improvement (like most tessellation in Crysis 2).
Because there is nothing on Nvidia hardware that is much weaker than AMD. except maybe Direct Compute. We don't know if Nvidia's poor performance is a result of AMD involvement. There is no way to know. But isnt it a coincidence those Nvidia problems only happens when AMD implement DX11 features are turned on? Similar coincidence that Nvidia implemented DX11 performs better on Nvidia hardware. See the problem here? Programs like TWIMTBP have already shown to hurt consumers more it helped. What makes you think AMD GE is any different.