But there is a limit to that, right? If a state passed a law requiring that all licensed OB/GYNs perform abortions, would a long-time Catholic OB/GYN be an "irresponsible selfish asshole" for disobeying it? Perhaps you would say the person should find a new job. But that is not obviously a fair solution, considering that the person has worked as an OB/GYN for a long time, before this law was on the books. An easier solution for everybody would be to simply change the law. In this case, that just means letting somebody else sign the license (and yes, that is what eventually happened anyway).
The Supreme Court simply said that the IRS acted within its power in revoking Bob Jones University's tax-exempt status. There is no reason to think that the Court would rule differently if the IRS attempted to do that to Notre Dame (of course, they would more likely target a school like Christendom, or some other school that is less iconic and easier to destroy). All that matters is that the policy is a "fundamental national public policy." Liberals, and a majority of the Supreme Court, regard same-sex marriage as a "fundamental national public policy." In other words, there is no ground of principle for preserving ND's tax-exempt status. Simply grounds of expedience- it is unpopular to take it away at the moment. But this moment will pass, and then nothing will hold them back. And that should startle all of us.