doesn't feel like ageism, this sounds more like the valuation of confidence. A confident person isn't going to stick around if you don't keep giving him or her promotions.

And you know? not everyone values confidence. I know I don't, mostly because I am very confident myself, to me, having an employee willing to take huge risks is pretty worthless, because you know what? I can do that myself. I want someone smarter than I am. Besides, people who are confident don't stick around very long.