Lots of times, I don't know what "the Church" means when Catholics use the phrase. I don't know what you mean in that quote.
I would not take my car to be fixed to a mechanic who owned several cars that had problems he could not fix. By their works, you can know people. Does a good tree bring forth bad fruit? I can study the origins of the Catholic Church's teachings on birth control -- back to Augustine and no further back. He invented those ideas. The Catholic Church still retains many of his ideas; and there will not, cannot be,complete reconciliation with the Orthodox Church as long his Augustine's invented idea about "original sin" remains a doctrine of the Catholic Church. Pride is the problem. Sometimes the Orthodox Church retained correct doctrines when Rome wandered off, and that is a problem that only Rome can fix by admitting its error, admitting there is no precedent for their idea of original sin before Augustine invented it.
I admire Peter -- I love him -- for his ability to change his mind easily when someone else was right and he could see it. Would to God his successors could do the same. Peter knew that harmony in the Church depended on his ability to see when others were right and to admit he was wrong. The Catholic Church seems to think if they admit even once that their "infallible" doctrines were wrong, their whole world would collapse. No one would see them as having real authority or wisdom. It is pride. That attitude also drives people away when they see clearly where the Catholic Church is wrong but refuses to admit it.
If the sheep are thirsty, but their shepherd does not lead them to water, why should the sheep think? If they need food, and he does not lead them to food, what do they think? Let's get realistic. Sheep trust their shepherd because he acts in their interest, not in his own. If he does not act in their interest, they are likely to wander off. Yet the Catholic Church seems not to perceive how their failures often led others to go look for other shepherds. All they can see is what they want to see to justify themselves, that the others are false shepherds. They seem not to see how they could have created the problem by being poor shepherds themselves.
I was reading the Catechism one day and read about wounds to unity. It admitted that the Catholic Church had inflicted some of its own. I was thunderstruck that they seemed to think that statement was enough. What wounds? What were they talking about? Could anyone go to confession and say, "I have sinned," and have the priest say, "Okay, say some prayers and you can go now." He would not. He would want to know what sins, and rightfully so. A good priest is a blessing indeed when people can gain great insights in confession by talking to their priest. Wouldn't it be great if all the Protestants had someone to talk to like that, even if they didn't consider him a priest? A good priest can get people to understand things so they won't repeat them.
Yet so far as I know, the Catholic Church has not fully confessed to the wounds they inflicted on the Body of Christ. They say some things, but is what they have said enough? Not that I need to know or that it would benefit me; on the contrary, it would benefit them. I think they need to know so they can and will avoid the same mistakes.
This statement also boggles my mind. I have a question. No one seems to know when the Pope speaks ex cathedra and when he does not. Is there an authoritative list? If so, I never found it. Then I ask, why have this teaching if nobody knows what it means so they can tell when he's speaking ex cathedra and when he isn't?
One doctrine is known to have been made official by a Pope speaking ex cathedra. It also remains a stumbling block to unity with the Orthodox Church and other churches. Was it worth it then for a Pope to issue the statement? The Catholic Church survived for centuries without a clear doctrine on the matter. It would have survived in the future without it. Catholic theologians were debating it, and people demanding an answer. Here again, the Orthodox Church shows its wisdom by saying some questions are "controversial" and cannot be answered. People are free to think as they want since the Orthodox Church doesn't take an official position -- had not in the past and will not in the future; but Catholic theologians thought they needed to know about the matter of the Immaculate Conception, and Pope did not silence them by saying it was not a question appropriate for him to try to settle. As his position of holding "all truth" seemed to be in question, he decided to make a statement and say he had the authority. That was in 1854. Eighteen centuries of "not knowing" were ended. We have to ask how Christianity survived for that long remaining in uncertainty on this. It's clearly not part of the "truth" received by the Apostles and handed down by Tradition.
I find it unnecessary and unfortunately also a stumbling block to unity. It was an attempt to "know" things men do not need to know. I could sit next to someone in church peacefully if he disagreed me on this question. Arguing about it isn't worth it. I think the Orthodox Church is right in how they interpret:
Titus 3:9 But avoid foolish questions, and genealogies, and contentions, and strivings about the law; for they are unprofitable and vain.
Where is there any profit in the doctrine of the Immaculate Conception? I don't see it. I don't see how it helps Catholics become better Christians, and I don't see how not believing it hurts those who don't. To me, it's not worth disputing and creating greater schism, putting an unnecessary obstacle in the way of reconciling others to the Catholic Church. If the Popes don't see it that way, then I guess they don't; but I wish they could see how they have made it so hard for others to establish unity with them because they want to right and don't want to say to anyone else, "Yes,I think you're right and I was wrong." They undermine their own authority. They do not see how Judah did not lose any authority when he said about Tamar, "She hath been more righteous than I." He became right when he said that. He would have undermined his familial authority by not admitting it. People would have known he was wrong and wouldn't admit it. Who would trust him then?