many times it seems it's more about the right timing and "fit" to a program than what coach. Some previously successful coaches fail and some previous failures succeed with a change of location.
So, can't blame the AD and boosters for trying a change if the current situation isn't working.
Of course, there's a fine line with giving the current coach the extra time or maybe the extra support to succeed after a few bad seasons and just pulling the plug.
sometimes I think it's the failure of the AD and leadership, they don't want to look in the mirror, so blame the coach and hire another guy.