You probably don't realize it, but that's a rather patronizing attitude. Not everyone works the same, and we don't all need co-founders to "to cheer [us] up when things go wrong."
Right, and a lot of people lead quite functional lives with just one leg. But I don't think anyone chooses that route if they could help it.
I don't mean to be patronizing (I don't see how it remotely is). Going at something with a partner isn't a requirement for success, nor is it only for "cheering up." Investors like to invest to successful ventures, and a business partner is a nice assurance for them.
But go ahead and show 'em, you rebel without a cause. ;)
