I am founding this company http://www.onista.com (A Social Marketplace) and so far I am doing it all by myself. Didn't have any issues yet and I am very well on the course to launch it in Summer. It is true that it is taking me little longer time than what I could have done with one cofounder.
But again, why should I expect a stranger to take risks with his/her career, make sacrifices and be passionate about my idea. After launching http://www.onista.com if people like it, then I am sure I will get cofounders.