The reason behind this is not CryTek. The ones who did this stuff is nvidia. They wanted to show how good the tesselation on cards are and also probably make AMD cards explode. They overdone it.
It was probably Nvidia that threw money at Crytek for it to pump up the game with a billion tessellation models, and Crytek internal managers probably told modelers "okay do a bunch of tessellated models now that they want us to showcase their tech." So they probably scratched their heads and were like "alright let's just blow up whatever the hell we can."
Tessellation, in the short order, really adds little. You might get nicer fine details but at the end of the day who really gives a stuff about a closeup of a brick wall?
