Yup, the best manager I ever had (by far) did not want to be manager. But she was made manager when half our team was laid off (including our manager) and she was the most senior of the bunch left. She was amazing because she was good at telling higher up's "no" when they would try to take advantage of our team.

The worst manager I ever had desperately wanted to become manager from a group of IC's and brown-nosed his way into the job. His first day as manager he says "I was promoted to manager because I can do all of your jobs better than you can". He could not. He was horrible (and was eventually fired).