A general manager for a basketball team can mean lots of different things, depending on how you want to run the organization.
(http://en.wikipedia.org/wiki/General_manager_(basketball)) I'm not saying that we shouldn't be able to control a lot of the coaching. I'm just saying that the game ought to preserve the option to let the coach make gametime decisions. And I don't understand the difference you're making between team management and franchise running. I think there's a continuum of responsibilities between head coach and franchise owner that this game simulates. And I think it's good for the game that we can choose to operate more as a coach or more as a owner (or somewhere in between).
All that said, I think it makes no sense to have a "Let Coach Decide" option if there is no Coach staff person. There ought to be a fourth staff slot for coaches. That way, if you want to play LCD, you have to invest in a good coach to get good results.