Mary had been venerated since Early Christianity, and is considered by millions to be the most meritorious saint of the religion. The Eastern and Oriental Orthodox, Roman Catholic, Anglican, and Lutheran Churches believe that Mary, as Mother of Jesus, is the Mother of God and the Theotokos, literally "Giver of birth to God". There is significant diversity in the Marian beliefs and devotional practices of major Christian traditions. The Roman Catholic Church holds distinctive Marian dogmas; namely her status as the mother of God; her Immaculate Conception; her perpetual virginity; and her Assumption into heaven. Many Protestants minimize Mary's role within Christianity, based on the argued brevity of biblical references. Mary (Maryam) also has a revered position in Islam, where a whole chapter of the Qur'an is devoted to her, also describing the birth of Jesus.
Try to answer this question if possible (otherwise reply "unanswerable"): What is the basis for Mary's diminished role in Protestantism?
brevity of biblical references