I'm intrigued that none of you have mentioned Visual Manoeuvring (Circling) approaches, which are routinely conducted by CAT aircraft around the world in much more challenging circumstances than the CAVOK, no traffic situations you've been discussing. If airlines and regulatory authorities are happy to approve scheduled pax flights day and night into airports where - in at least one case I can think of in the UK - the only way to land on the normally into wind runway under IFR involves an IAP downwind to the opposite runway then a visual break to fly a low level circuit, often just under the cloudbase, to land into wind, then where on earth is the problem with visual approaches when you can see for miles?
NS