In my view it's because often, when co-founders fall out, the company is either badly damaged or ends. This can happen early or after many years. So the require

In my view it's because often, when co-founders fall out, the company is either badly damaged or ends. This can happen early or after many years. So the requirement for a good co-founder is really high. There's not necessarily anything to indicate that this critical relationship will be a success because anything can happen, even with the right co-founder.