The only reason to install them is to meet some prescribed need from the UCI so unless any of us are planning on racing UCI sponsored events it should be of little concern to the club rider or touring rider or everyday rider. I never gave it a second thought when I bought my MTB except that I wanted Hydraulic rather than cable operated disk brakes.

To me the issue of additional damage during a crash is not as big a deal as some make it. The big problems in wheel changes and different stopping distances in tight packs. Crit races just magnify those braking distances and road races magnify the tire changes.