If that were the case, we would all be saved except for Jews. God's will was made very clear in the commandments. Love God above all else, and Love each other.
Devout Catholics happen to love everything associated with God. The fact that we think Jesus mother was special and commemorate her and all those who served God, doesn't take away from God, in enhances our Love of God. On a practical level it also serves as a reminder of how to love God. Jesus' mother was obedient and although she endured great sufferring, she never lost her faith. To me that message was a beautifull gift from God.
Sadly, the RCC carries its teachings into an idolatrous worship/veneration/glorification/prayers to a woman who was exactly as fallen as you or me, and who was saved exactly the same way you and I are saved -- by grace alone through faith alone in Christ alone.
No bodily assumption into heaven of Mary. No sinless conception of Mary. No supernatural intact virginity of Mary after Christ's birth. No worship/veneration/glorification/prayers to anyone other than the Triune God alone.