Actually you need to go deeper to understand that it is actually the teaching of the Catholic Church.
"Extra Ecclesiam, Nulla Salus"
Outside the Church, there is no Salvation.
St. Ephrem:
The Virgin Mary is, again, the figure of the Church, which received the first-fruits of the Gospel. Mary saw Him, as representing the Church. . . . Let us call the Church by the name of Mary; for she is worthy of the double name.
St. Augustine:
The Woman signifies Mary, who, being spotless, brought forth our spotless Head. Who herself also showed forth in herself a figure of holy Church, so that as she in bringing forth a Son remained a Virgin, so the Church also should during the whole of time be bringing forth His members, and yet not lose her virgin estate.
Read on Isaiah 62:5.
“For as a young man marries a virgin, So your sons will marry you…” - Don’t you find this amazing. Mary concludes a covenant of salvation by becoming Christ’s bride, a role usually assigned to the Church.
For if we don’t have devotion to Mother Mary, then we don’t have hope in the perfect work of God. For Mary, is the perfect work of God. To deny this is to deny the Immaculate Conception dogma defined of the Catholic Church