Originally Posted by lucid
... Weight of the rotors constitute thermal mass for heat to be dissipated effectively without melting down everything in sight. Creating friction between the pad and the rotor by applying pressure is just one part of the deal. Dissipating the generated heat effectively is the other. If the rotors do not have adequate thermal mass to transfer the heat and dissipate it away from the calipers, the brakes will be in trouble. (Keep in mind the majority of the rotor is not in contact with the pad, and is surrounded by cooler air, and thus heat transfer via convection between rotor and air.)
Wow! No wonder you go by lucid.