In his last days Luther saw the excess of the mariology...and he addressed it
Do not hang your ark on him cause it would be a no sale
From a Luthern answer site
Since prayer is worship (Luke 2:37), and since worship is to be offered only to God (Revelation 19:10), to offer prayer to anyone but God is idolatry. Luther, indeed, did have a high view of Mary, but only in a Biblical sense of honoring her memory as the human mother God used to bring his incarnate Son into this world. While there is nothing wrong with asking other Christians in this life to pray for us, we are never encouraged to pray to them. In fact, as Isaiah 63:16 indicates, the saints in heaven appear to have no direct knowledge of our daily lives. Their concern is rejoicing in the presence of God.
In addition, Mary is a forgiven sinner whose place in the family of God is founded on the grace of Jesus Christ just the same as ours. Praying to Mary obscures the beautiful truth that every believer has equal open access to the throne of God (Ephesians 3:12). It is slap in the face to God's gracious Fatherly love for us to pray as if we need Mary to intercede for us. Jesus Christ alone is our intercessor at the right hand of the Father (Romans 8:34).
Do you know how creepy that sounds?