This is actually something I've considered quite a bit and I've come to realize that I think there's a certain amount of megalomania necessary to be a "primary

This is actually something I've considered quite a bit and I've come to realize that I think there's a certain amount of megalomania necessary to be a "primary decision maker". You have to genuinely believe that you can make better decisions than most. In my case, however, the motivator isn't megalomania so much as my need to address problems - I see problems everywhere and in every case in which I've worked for someone, I've largely been forced to just stew in them. To some degree I think I agree with you that what this ultimately comes down to is trust - trust that I can fix this, or that I can make blah happen. I've worked for some great people who did trust me, but unfortunately someone up the chain didn't. To make any real impact I think you have to be willing to take some serious risks and when you're that far away from the problem, it's hard to imagine why those risks are worth taking. In any sufficiently large organization, preaching a disparate vision is bound to hit a wall, because somewhere in there is another guy just like you - someone crazy enough to start a company because they believe in their own vision.