Do people not turn IRL?
I find that using the thumb sticks for rotation makes me feel a lot more iffy than turning on the spot in real life. I've got 100% used to smooth locomotion now, forwards, backwards and sideways, but still not 100% on rotation if I do it using smooth or even jump motion using the thumb sticks.
I understand that if you're playing sitting then turning IRL is a slight issue, unless you use a swivell office chair!!
If there another reason why people wouldn't just turn on the spot?