The only thing I could think of that may be crytek's defence is that DX11 has been implemented from the beginning for PC, but EA have forced the release date across all platforms.
They were not ready so pulled DX11 and will tweak while game is being shiped and patch on launch day or few days with DX11 glory.
On the other hand if it is a bolt on then it sucks. All DX9 games with DX11 added on look exactly same almost and just a huge fps hit.
Also comparing the multi player Crysis2 to Crysis 1 single player is not fair, as crysis multi also looked bad in comparison to SP.
But I could be completely wrong, the game is probably just a console port afterall.