The oil tanker in Dakar was apparently keeping just as good a watch as your two-hulled friend intends to, and, unfortunately, just as good a watch as the 45' sailboat seems to have been . Darwinism is tough, but can be effective. I sleep better knowing one of my crewmates is on watch for all of us.
I am pretty sure that tanker was from Norway - if I remember rightly -and they are pretty serious sailors. They went into a panic when I showed them the mast and rig - no sails BTW - hanging from their anchor. I simply refuse to not have someone on watch when we are at sea or anchored in an unknown place the first few nights. In any case it is my job to insure that a proper watch is maintained at all times...besides I agree with you it helps one sleep better and live longer.