I was just talking to the guys in my local shop about this subject. Apparently, the original application/idea of tubeless was to prevent pinch flats on non-road bikes, running very low pressures. Then somehow it morphed into "tubeless is superior in every application, including road!". It never made sense to me, and our discussion seemed to confirm it. Not practical for road, because of the lack of volume of air, and the extreme pressures. Also, tubeless was never meant to stop a puncture leak, as it usually just ends in a geyser of sealant, and a flat tire. Road cycling is the ultimate in "gotta be first/gotta be trendy/gotta have the latest thing" regardless of practicality, or necessity.

I don't have personal experience with tubeless, but since I don't flat very often (knock on wood), I haven't found it necessary on the road.