the top team spent 100s of millions (the lower teams 10s of millions) developing the car to work in a certain way the FIA then mandate a wrong part to use in the drive chain
its like saying you must run your monaca gearing at monza
or a fuel pump that doesnt flow enough fuel
or in other sports terms asking a marathon runner to carry a fat bloke for a few miles
it may spice up the racing but its isnt in the spirt of the sport
having a tyre that isnt ment for the job by such a margin is nie on dangerous and flys int he face of saftey
it could be said that the kubic / vettel incident was a direct result of this tomfoolery