Notre Dame is a parasite, and all they did was find a new host. In many biologic parasitic/host relationships there is a symbiosis by which both parasite and host are benefitted by the arrangement. Notre Dame would have you believe this is the case. It is not, and was not with the Big East, and it is not with the ACC.
Because Notre Dame is really a parasite, but not one that generates a symbiotic relationship with it's host in athletics. Notre Dame is more like a virus. The host becomes inoculated with the virus, and the virus takes over and uses the host cellular machinery, to build itself for it's own purposes.