Rubbish. Its like putting I winged keel catarmaran against a single hull. You can't just take that argument based on your own bias 
Whats a winged keel catarmaran? If you did manage to bolt a winged keel to one then i would take the mono hull any day of the week!
By its design a cat does not need a keel. If however you mean a curved dagger board that creates a foiling cat then you are back to your arguement over money and size.
I would not put money on a 30ft day boat beating an AC72, but I would put money on a foiling moth beating a Prout 72ft cat!
Conversly I would much rather be in Volvo 70 doing 35+knts in the Southern Ocean than in any of the AC or Extreme 40 boats!
A cat can be faster than a monohull due to apparent and true wind issues which the bloke on the drawing board can design around
Also why Adrian Newey is looking to move into yacht design apparently
He who has the most money (Larry Ellison) finds the advantage! Exactly how the F1 car beats the bike.
And the fastest thing on water powered by the wind @65+ knts is the Vestas Sailrocket, technically a trimaran and nothing like the average punter sails!