The argument is valid and i think the question needs asked. The problem we have is that in Catholicism, Mary is taking a place where God alone has already supplied our needs via the Holy Spirit, who is inside Gods children. Its like saying the Holy Spirits intercession for us in prayer is not good enough, so we need Mary to intercede as well. God never commanded this prayer and it contradicts the Word.
I'd say we can go even further and point out that Jesus...the only perfect, spotless Lamb of God became the only acceptable sacrifice in the Father's eyes. This act was carried out not only to cleanse us from our sins, but to take away the veil which stood between us and God...He alone is intercessor...He alone has gained that glory and God does not share His glory with another says the Bible. Hebrews makes this all much clearer for us...
Hebrews 2:10:
In bringing many sons and daughters to glory, it was fitting that God, for whom and through whom everything exists, should make the pioneer of their salvation perfect through what he suffered.
Hebrews 2:17-18:
For this reason he had to be made like them, fully human in every way, in order that he might become a merciful and faithful high priest in service to God, and that he might make atonement for the sins of the people. Because he himself suffered when he was tempted, he is able to help those who are being tempted.
Hebrews 4:14-16:
Therefore, since we have a great high priest who has ascended into heaven, Jesus the Son of God, let us hold firmly to the faith we profess. For we do not have a high priest who is unable to empathize with our weaknesses, but we have one who has been tempted in every way, just as we are—yet he did not sin. Let us then approach God’s throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need.
...freedom to pray, "Abba Father" was won through Christ's work on the cross. To insert Mary...though blessed above all women...is not a clear understanding of what Christ won for us on the cross. God does not share His glory with another.