Sorry about your troubles, OP. These phones (both 6 and Plus) have larger screens and are heavier; therefore I think the screens are more prone to crack. I've dropped my 6 Plus in Apple leather case 3 times, once off bed onto rug, once from waist to rug, and once from lap onto concrete sidewalk while sitting outside a cafe and it has emerged unscathed. However, I don't like the sound it makes when it hits the ground, definitively more thunk to it than my 5s.
These are heavier devices with more surface area and thus more velocity in a drop/fall and greater impact with hard surface.