I am a single founder who constantly wonders if I should be. I have founded 2 startups before and both imploded solely because of founder issues. One had 4 of us and I spent more than half my time playing referee. I will never go through that again. AFAIC, nothing is more important than being in business with the right people (except having plenty of customers, maybe.)
I am working hard and steady on my new venture, but I do not actively recruit potential co-founders. I freely share what I'm working on (hinting at opportunities for co-founders) and sit back to see what happens. Since I believe the single most important trait of a good co-founder is sheer determination, I hope someone will come to me insisting, "We should do this...," "I could do that...," "Let's try this...", etc. Sorry to say, this strategy hasn't worked too well, but I'd still rather be alone than be with someone who doesn't push as hard as I do.
I know about half a dozen excellent people who I'd love as co-founders, but all have mortgages, families, and other commitments. Our startup would always be a child to me, but only a step-child to them. So I don't push.
I understand pg's concern about single founder startups; they're a lot of work! There are many times I wish I had someone to share with or help me out. But under the circumstances, I'd rather plow along, always positioning myself to have a co-founder, but just as ready to launch alone if need be. I'm not afraid to do that and I don't think other single co-founders should be either.
OP's links were great and for a single co-founder, a little reassuring. Who is fauigerzigerk? I don't recognize him here.
OP's discussion about the "bozo" factor was just silly. Sure, if you're still in school, you should have no trouble finding suitable co-founders. But as you get a little older, there are many good reasons for being a single founder without being a bozo. Those of us who are should remain open to accepting the right co-founder, but in the meantime, just keep on working hard.