Ten quick points.
1. Mary receives considerable attention, of course, in the nativity scriptures and at the time of the crucifixion. Otherwise she is rarely mentioned in scripture.
2. Her role when Jesus was 12 raises questions. I know the traditional response which sounds weak to me, as I am still amazed that Mary and Joseph didn't notice the absence of Jesus for a whole day after they had left Jerusalem. Then, alas, it took them three days to find him - in the temple! - after they returned to that city. At that point, they scolded Jesus and he seemed to scold them in response.
3. On the two occasions when Mary is mentioned between that event and the crucifixion, Jesus seems a bit dismissive of her. Re-read Matt. 12:46-50 and John 2:4. In both instances one would have thought he would have encouraged those present to venerate his mother, but, instead, he behaves as though she is somehow an interloper, certainly not that central to his message certainly. Woman, what have I to do with you? And, who is my mother? Etc.
4. Mary his mother apparently did not come to the tomb on that first Easter morning, Jesus didn't seem to appear to her after his resurrection as he did to others.
5. While Mary is mentioned once in passing in Acts, the Pauline and other epistles do not mention her even once. You would think that if she was supposed to be so central in church doctrine and ritual that all these instructions sent to early Christians would have at least made mention of her.
6. The passage in Revelation which the Church interprets as referring to Mary is questionable (at least in my mind). It could/should have been much clearer.
7. A key verse challenging (again, in my mind) the perpetual virginity of Mary is Matt. 1:24. Most translations suggest that after the birth of Jesus Mary and Joseph lived the life of a husband and wife, including marital relations. To me that makes them normal and presents no problem. How could one possibly object to this intimacy? I find the effort to link virginity to purity absurd. Is there anyone purer than a devoted, loving mother or father?
8. The references to the brothers of Jesus need to be taken into consideration. Could they have been cousins? Maybe. But maybe they were brothers. Fine, if so.
9. I taught mythology on the college level awhile back, and the virgin cult was strong in the pagan world of that time. The myths of Isis, Cybele and others were strong. It makes sense that influences from these competing mystery religions could have had an impact.
10. Regardless, all Christians should and do honor Mary. The Bible does say that she is 'blessed among women' and that 'henceforth all generations will call me blessed". The Protestants may have gone too far in downplaying her, but I wonder if Catholicism hasn't gone too far in the opposite direction. When I attend Mass, and when I am present as the Rosary is recited, it always strikes me that Mary is treated like a goddess who exercises enormous power over Christ. Going 'through Mary' seems to be a major cornerstone of Catholicism. Add to this the power attributed to dozens, even hundreds of saints, and Catholicism can come close to resembling Hinduism (I spent time in India), with its many demigods and goddesses important in spiritual scheme of things.
Yet, millions find comfort and meaning in all this, so fine. No problem. I'm simply pointing out some of the reasons why Mariology has distanced me from traditional Catholicism. It would be so much easier to be a believing Catholic if more freedom of belief were permitted instead of the insistence upon accepting each and every doctrine and dogma. This smacks of authoritarianism that many of us reject, My guess is that advanced education plus the evolution of democracy have played a major role in all this.
God bless everybody. If your faith leads you to worship God and live in love and charity with others, go for it. Someday we'll know the full truth which, I suggest, the human brain simply would/could not comprehend until the world beyond. Probably none of us, and no church, have come close to that truth here because of our finite minds. I suggest more humility and less tribal arrogance which stems from man's innate sinful nature, leading us to view our opinions and our clan as superior to all others.