To be fair, even if they loved IW they would probably say that just to be better received by the old fans.
More like, to be unfair. When you are talking about gameplay concepts, lying just to please old fans would be... idiotic. While Deus Ex almost definitely has a special place in many old gamers' hearts, just kissing up to that crowd would be silly. Especially since it's now been, what, 10 years since DX came out, and it's a PC/PS3/X360 release...
Except that then they go back to IW's character development system instead of the original, for once.