Hey there guys. Great discussion on everyone's part. Here's my two cents:
As a recreational and technical diving instructor as well as an avid solo diver, I tend to agree with many 'sides' and arguments. The fact of the matter is that if a diver feels confident with his/her ability, there isn't a scuba police force I am aware of. If I choose to dive, but can't find anyone on short notice to hit the water with, why should I have to suffer. I dive with plenty of redundancy in dive spots I've been to hundreds of times etc etc
It's a conscious choice that can be made by anyone whom follows certain rules. Experience, maturity, planning, quality gear and careful execution of the dive plan are a must.
Sea you in the Deep Blue!