This isn't just a matter of defending solo founders, but perhaps we should consider using some clear standards like one person profitability to make being a single founder able to be more of a conscious decision than a last resort.
there just seems to be a lot of posts on this lately. I think as far as it being a "last resort", it all depends on how well you know yourself, and, in the case where you're the kind of person who needs a cofounder, how lucky you've been in finding someone compatible.