Whether change can happen under Ferentz or not, I don't think he deserves the chance. There were already a lot of legitimate reasons to want to see him move on, but twenty years of (best case) willful ignorance about systematic harassment and mistreatment of black players by his top assistant and another eight years of the same behavior by his own son is the end of him, for me.
I can't in good conscience keep giving support to the athletic department, direct or indirect, as long as Gary Barta, Kirk Ferentz, and Brian Ferentz are still employed. (There are probably others that need to go, too, but those three would be a sign that this is being taken seriously.) I know that it's a fairly meaningless gesture, given that most people probably won't make the same decision and that my support probably doesn't amount to more than a few bucks anyway, but doing nothing means nothing will change.