No you're the only one who has come up with it after such a long time.
Crysis is still the most CPU&GPU straining game , Crysis 2 as far as hardware requirements goes was absolutely nothing compared to Crysis.
This basically means that Cry Engine 3 was really not as demanding as Cry Engine 1 on it's hardware, thus the more FPS on even a rig that might barely play Crysis.
People have been reported being able to complete Crysis 2 with ease on machines that gave them unplayable frame rates for Crysis.
A lot of it may also be because of the optimization of the CryEngine 3 as compared to the more complex and base founding engine CryEngine 1 which was used for Far Cry and Crysis.