First of all - you are right about NCL. It is just a GREAT thing to do for the curise industry and it is something long overdue. Single cruisers deserve a break and this is a way to really introduce a lot of people to cruising who never would have tried it before.
The setup is so perfect for a single person - you automatically know who and where the single people are onboard - and you can easily find then almost whenever you want.
But, sorry, but I am sure your wife would say you're just too good lookin' to be left alone in a group of single cruisers.
I'll tell you what though, at that price I see a lot of couples booking those adjoining cabins - whether they are married (but prefer to sleep alone - it is more common than you might think) or same-sex friends. That is a great way to travel with a friend and also have some privacy at a reasonable price.