Why are people so obsessed with finding a co-founder?

I can understand why someone would want a technical co-founder (someone who actually develops the product for free). However, why are even technical founders trying so hard to find a co-founder? Many times, they are looking for business co-founders, who will take like 50% of the company. If you need extra help but can't afford, why not just hire freelancers? I noticed that a lot of people who are seeking a co-founder don't even really need one. They just want one "just because." Why is that? I can never imagine doing that. Am I missing something?