I own a small-displacement cruiser, but have had a lot of bikes over 25+ years of riding. I use rear-only when powering through a sweeping turn at about half-throttle. If you need to cut down on your pace or correct your line, but don't want to back off on the throttle which will will make the bike "stand up", then drag the rear a little, which also has the effect of dragging the front end into a turn. In more-or-less straight line stopping, use both brakes.
Different rules apply for dirt riding, but I'm not a dirt rider.