Catholicism puts great emphasis on the importance on the Mary, the Mother of God. It honors her and insists upon her perpetual sinlessness and perpetual virginity. And in my observation, it seems as though this high opinion of and devotion to Mary is integral to Catholicism.
This is very much in contrast to Protestant traditions which insist that Christ is of sole importance. In the loosely-quoted words of many-a-Protestants:
Why wouldn't a Christian's devotion be to Christ alone? Why set up intermediaries where none are needed? And why contort Mary's role as having any more significance than Christ's physical, human mother? Doesn't that smell like idolatry to you!?
So, why is she so important in and seemingly integral to Catholicism? Is there theological, symbolic, or spiritual significance?
Do they just assume if they can convince Mary to pray for them, Jesus has to listen because she's His mom? (Lest he be put on a heavenly time-out?)
For the sake of Christian unity or otherwise, why can't the Catholic Church just drop the Marian devotion?
Addendum/Clarification: Is the theology and practice surrounding Mary roughly as integral to Catholicism as the doctrine and meditation of the Holy Trinity? Eliminating the doctrine of the Trinity would fundamentally change the Catholic understanding of God. Would downgrading Mary also change the Catholic understanding of God?