Because the schism between Rome and Eastern Christianity was already in play before it became "official" with the excommunications. The two halves of the faith were already far apart in organization and practice. The game wouldn't make any historical sense if Byzantine vassals were paying attention to an excommunication of their emperor from the Pope in Rome in the 800s. With a schism already in place at the earliest start, we avoid a lot of silliness.
But aside from that, the game does have mechanics that will approximate a world-changing event like the Reformation. Rethink for a moment what happens when moral authority gets low, and think about how heresies are structured differently than Roman Catholicism. And then go read about how Protestants felt about these medieval heresies.
You'll see that if a heresy takes hold in Europe with enough backing from secular authority, you are more or less in the same situation (sans colonial empires and some technology) as rulers in the 16th Century found themselves in. Hell, I've created a heretical England that used religious authorities to weed out Roman Catholics and went to war with Roman Catholic Irish realms. Sound familiar?
True, but I find it kind of silly that two religions that have coexisted for 400 years would still consider one another Heretical and would Holy War one another, there should be a point, where the Heresy becomes a different entity.
After the peace of Westphalia, Catholics and Protestants had a schism-like divide. Protestantism became it's own independent entity that was not constantly in conflict, for the most part, with Catholicism.
And yes, when MA is low heresies pop up everywhere! And I get your point, but I think a mechanic similar to mine should be implemented, or the entire Heresy system reworked.
Once you get large enough, the heresy, in essence, becomes de facto, another schism. Often you stabilize your realm and it's all good. But that "Heretic" opinion is very awful. It is much worse than "Differences in religion" don't you think?
After 400 years of being well established religion with your own practices, everything should settle down, which is what I propose should happen via schism.
Does that make sense? I have a tendency to loop back on myself.
