Why is it so hard to form startup teams?

I am organizing some material on the subject of "venture acceleration for solopreneurs" and understanding this from different perspectives might help. There are an awful lot of us who have tried but never succeeded in forming teams. Others in the same boat out there? Any theories as to why?

Darn - no one? I guess this is too buried to get an answer now, but the issue still is important to me - I guess I will try Quora or something, or maybe even my entrepreneurs community.