I guess I do because being Italian , that's what I grew up with . It doesn't bother me if other people do ! If you would have seen some of my Mom's relatives all together talking , you would thought they were talking sign language ! The gestures that my Mom would make at my Dad used to make us kids laugh . Everyone is different !
My wife does more than I do, but she's Italian so I'll stereotype her. I do at times, like doing sign language, signaling my platoon, in the cockpit I have to signal the ground crew. Other times would be getting cut off in traffic, They can't really hear what I' saying, so while in mid-rant I use the universal friendship salute (the rigid digit)