Firing people for their opinions is actually fine - if you believe that certain types of people don't deserve rights, for example, and your company has those types of people in it, that's a problem. Freedom of opinion is not guaranteed.
Implementing this meant that people who worked for the state, and other neutral institutions, had to work with others who they honestly believed were heretics that would go to hell. Both they and the institution had to learn to keep their tribal conflicts—nominally religious and doctrinal, but in practice tribal—under control. This was difficult, but very valuable to all sides. The truce enabled mutually beneficial cooperation and the prosperity that entailed.
Centuries later, some tribes find themselves in control of certain institutions. The truce, the principle of neutrality, restricts them, and they see little benefit from it. "Why not violate it, and start a fight over this issue where we have the upper hand? We'll win!" Sometimes this takes the form of arguing tendentiously that the other side violated the truce first, and hence their attacks are in fact justified retaliation. Other times they seem ignorant of the value of having a truce, and are likely ignorant of its history (which is not taught well). So they start trampling on it.
Depending on what we imagine their motives to be, and how narrowly we consider them... On that issue in isolation—gay marriage—it's probably "rational". However, violating the truce makes it easier to do more of that, both for them and their opponents. On this issue they have the upper hand, and they'll win. On abortion, they have the advantage, but less so. On other issues (such as putting biological males in women's sports and women's prisons) they have minority support, and if they keep up their attitude of just fighting because "why not?" (subject to tactical considerations), they will provoke the opposition to fight back more and harder, and eventually they'll lose ground on the issues themselves—to say nothing of the costs of the fighting and the lost value due to the broken truce.
They are short-sighted, ignorant, aggressive little barbarians who start smashing the thing in front of them, unaware that it's a pillar holding up many things we and even they hold dear. They know not what they do. I guess this is where we see the deficiencies of current education.