People of the type needed to run an organization like the ACLU are rare. You need people who are willing to stand on principal even when it makes them unpopular, and who are skilled enough that they could be making a lot of money for themselves in the corporate sector, but are willing to forgo that. The failure mode of this is attention seeking "activist" types, and people who don't have the skills to cut it in the for-profit world. For profit businesses also have a failure mode like this too, where the initial leadership who got there off being innovative and willing to take risks are replaced by boring MBA types who are just there for the paychecks. But in this case, the people taking over are both more in line with the objectives of the organization (to make money) and more competent than the incompetent / activist types who take over non-profits.