How on earth his opinion could "negatively impact how business is done"?
They're firing him not even because of his opinions but because he's just bringing more "bad" than "good to the compagny.
At the end of the day it's not the "compagny taking a moral standpoint" but "solving a compagny problem" in the most simple way
So if I understand your argument correctly, if people hate you then it's OK to fire you? I'm sorry, this makes no sense to me.