The board is chosen by the shareholders in the absence of some arrangement to the contrary (e.g. the special class of shares), and for a large publicly traded company, the major shareholders are generally going to be large investment funds, i.e. Wall St.

The main thing the special class of shares does is make it hard for them to oust the founder when the founder doesn't want to retire. Once they choose to, they either use their special votes to choose a worthy successor, or they stop caring and you get the default MBA you'd have had regardless.