Is this inherent in the human mind or are you making an untestable claim?
When it comes down to it, we don't do well alone.
If you want to have word play and add additions like.. I'm alone and a startup, but I have a fantastic group of individuals I surround myself with...or I have a family that really cares. That's not really alone is it?
I don't see many isolated entrepreneurs that stay alone and never give up the control--and grow. How would you hire and instill passion? How would you not have a motley crew of cog creators?
Having a partner, or general support, is the groundwork for a network. A network is what allows us all to play, create, and grow.