I think one of the reasons for Mariaphobia among Evangelical Protestants is the fear that Marian devotees get sucked into mysticism. It conveys a sense of something mysterious, akin to magic, enchantments, wishes and wishes granted. But it came to me that some people have it backwards after all.
But let me point out first that this fear of mysticism, if coming from a distaste for the supernatural, and preference for enlightened discourse, should not belong to a Christian. Being Christian is supernatural, and being enlightened supernaturally. My main point, however, is that the burden of mysticism is not on our Lady. What matters to us is that it is on us Christians. Because everything that we must become, in a mystical, supernatural way, was fulfilled first, physically and directly, but also mystically, with our Blessed Mother.
We are temples of the Holy Spirit? The Blessed Virgin was physically so, which bore physical fruit in the Incarnation of the Word in her flesh. We are in the body of Christ? Our Lady was there before us, physically one with the physical body of Christ. We are to be sanctified so as to become Christ and to become Christ-like? Our Lady was there ahead of us also, bearing Christ physically so that the world might be saved. We are to receive the fullness of grace? She was there first, as the archangel addressed her by title, rather than name: kecharitomene -- full of grace. We are to have the fullness of faith? Again, our Lady was way ahead. As St. Elizabeth exclaimed, "Blessed are you who believed that what was spoken to you by the Lord would be fulfilled." As the Lord affirmed himself: "Blessed rather are those who hear the word of God and keep it!" We are to be intimate with our Lord and Savior? Which man or woman has been as intimate with the Lord as the woman who was his mother, raising him up from infant to man?
So it isn't that mysticism surrounds Marian devotion. In fact, it surrounds us as well, and that is even more relevant to us. Every Christian should know the Lord's mother intimately. She is God's masterpiece among his creatures, whom we can look to for inspiration on what we must become as Christians.
So we shouldn't worry about mysticism and the Blessed Mother. What should worry us is whether or not we have enough mysticism in us. The right sort, like the Blessed Mother's.