As K6 says, it's up to the pilot to fly the aircraft, ATC have other things to do besides monitoring approaches. Apart from that a transponder doesn't necessarily give height above the ground, so the height on the ATC guys display may be totally meaningless in terms of approach height.
If you were flying a PAR approach then fair enough, you do what ever the guy watching the tubes tells you but
AFAIK they don't do these approaches at major airports although I'm willing to be shot down on that one.
PAR is certainly still in use at mil airfields.