This sounds like good advice to me. This YC requirement has led to something akin to "cargo cult cofounders" - getting someone else involved because it's "better that way". While I tend to think it is better to have one, it has to be the right person, not some random dude who you barely know. It's sort of a catch 22 in that it's got to be someone you've already known for a while when you start looking or discussing the idea of doing a company.