"...if you can have an animated model inside the cockpit, why to have only legs?..."
Because, when I see only legs, I've the feeling of sitting myself in an aircraft cockpit, making some kind of "amphi cabine".
Hard to explain it on the psychological point of view, but legs are less "personal" than hands

So, if I see hands in a "cockpit view", I can only ask myself : "who is in my aircraft". Reaction that I don't have, when I see only legs.
I can only mention Lock-On once again, I just feel right in a Su-27 or an A-10, seeing only legs.
Btw, no seeing the rudder pedals is really not an important aspect, to me at least.
Of, course, "legs" should be optional, for people wanting them, or simply switchable, for the guys whining for the little useless instrument hidden by their big feet