In an article about Bill Gates' retirement, Joel Spolsky says this:

"Watching nonprogrammers trying to run software companies is like watching someone who doesn't know how to surf trying to surf. Even if he has great advisers standing on the shore telling him what to do, he still falls off the board again and again. The cult of the M.B.A. likes to believe that you can run organizations that do things that you don'€™t understand. But often, you can't"

I think there's something to that. If you want to successfully run a business you don't really understand, you have to be willing to admit to what you don't know. The problem for a lot of managers is that they see that as a sign of weakness - and thus, they plow ahead with stupid ideas: "sure, lay off that development team now that the product has been delivered. Programmers are interchangeable"

You don't want a micro-manager who gets involved in every little detail, either - that ends up making decisions impossible to arrive at. Ultimately, I think good executive talent is pretty hard to find. Even if you have Spolsky's ideal, it's hard for that guy to step back, admit that his technical knowledge is dated, and let the junior guys run with things. Combining the type A drive of an executive with that kind of cooperative skillset just seems to be rare, regardless of what the starting career point was.