If employees can justify asking the boss to leave because of his personal beliefs, then they should respect the opposite and support the boss when he similarly asks them to leave for theirs.
It doesn't matter what his personal beliefs are, what matters is that he financially supported a law that would have forced others to conform to his personal beliefs. If your religion dictates that you shouldn't eat pork, or not to marry certain types of people, or to clip off parts of your son's penis, and you want to live your life by those principles it doesn't affect me so knock yourself out. All I ask is for mutual tolerance (people often overlook the fact that tolerance must be mutual or else it doesn't really work). And if someone does try to force those beliefs on me, I will confront them about it. And then they can ironically criticize me for being intolerant.