For some people it's down to peer pressure and for some it's trying to emulate their heroes. For some of us it's down to need when you start getting towards the limits. With rearsets you will not get the pre-warning and on some race reps the clearance is more than you'll ever need, ie it is possible to get your elbow down. Safe riding with the occasional track day has to be the way ahead or even combining training and track like the Ron Haslam School at Donnington. This is an absolute hoot and highly recommended.