Not taking sides, I will add here that I've seen tethers required by cat clubs before, and these were experienced cat sailors (really old New England 100 days). IIRC, they were required on the boat, but you didn't have to be clipped in.

Tethers, like PFDs, are tough. People have been trapped under boats and unable to escape without removing their PFD. Others have been saved only because of the PFD. Other than probabilities, one group isn't more "right" than the other.

Bring dragged behind a boat is no fun, neither is having the boat drift away from you with no rescue boat in sight. Would make the EPIRB and VHF on your person suddenly much more important, though...

Mike