Most passengers hate to sit with their back to the front. Yet, rear-facing seats are considerably safer than seats facing the front.
If an aircraft suddenly decelerates, your body still has the plane's original speed. As a result, you tend to fly out of your seat to the front.
Seat belts will keep you in your seat, but the risk of spinal injuries is high as was proven when Asiana Airlines flight 124 crashed in San Francisco on July 6, 2013.