You ask why DX 11.....!!!!
Here is ur answer with example of the enhanced "OLD" Unreal Engine 3.....
http://www.gamesas.com/forums/viewtopic.php?f=22&p=240675#p240675
Look at those Videos......
Funny thing is those features are still in development and there isn't an Unreal game that sport these features. Your point has been nullified.
Sorry but we not discuss about a Game who is use this. So u are nullified...

Fact is, this is DX 11 looks like....AND Cryengine 3 can do the same on most Graphicfeatures i think (not know).
Sadly the high technology isnt appear at Cryteks Office........too expensive for only PC Users, i think...on the other hand---who knows how much bought this Game if it use such DX 11 Technology?
If u look at PC Users bought Game.......lol...not so much!
Just speak for me and at looking at Unigine Heaven Benchmark as a Example.......i love Tessalation most and other Features too...and of course my GPU 580 can run it at acceptable Frames!
So much about my Point about it....
Regards