The Catholic and Orthodox operate based on the councils of the Church and episcopal decisions. Our primary function is to preserve the truths once taught. "Mother of God" is one of them; it was not chosen in 5c. for frivolous reasons, and people had very serious misunderstandings about the Christian faith then. If the Evangelicals do not want to teach that, why no one is forcing you. Neither Reader David or I, I assure you, plan to spend days on end arguing with the Evangelicals what to teach their flock.
If, however, someone is going to look at our teachings and erroneously conclude from them that Mary is God, or preexisted Christ, or what have you, we will correct them. This is why we have the Catechism.
If someone were to pick up a book of devotion to Mary on a train or something - You may not have the opportunity.
I do not believe that the episcopal decisions were taken lightly and understand the reasons for them and the meaning behind them. I don't always agree with the decisions made, but that is neither here nor there. I just know that in this world of confusion, we need to be very clear. You don't have people's ear like you did in the 300s. Why, today we would get a council together to discuss a doctrinal issue and Greta Van Sustern would preempt it because Brittany Spears was actually seen dressing modestly.