ALL inst arrivals are designed & flown when required for one single reason, to become visual & complete the approach to land (obviously) with vis ref to ground or water, one can disscontinue an appraoch at any time & for any reason, (some are mandatory reasons) it says nothing in the books about 'having' to complete the whole approach, if
VB want 'add' a little for good measure then that's their problem/right. (bunch of girls, only kidding)So most do it beacuse it's legal to do so, complete a circiling approach when they CFIT (see fit):-)
Capt Wally