The sibling I am closest to, spiritually speaking, is a practicing Catholic. I'm a Calvinist -- someone who processes Protestant convictions through Catholic hard wiring. Something about being raised a Catholic predisposes one to seeking global implications for his faith.
For me, as much as I respect my beloved fellow Christians of the Roman communion, the cult of the BVM is an insuperable barrier on the road back to Rome.
Meanwhile, I am grateful for the vast majority of theology and conviction we have in common.
So, in your opinion, God leads people to sin and damnation, and the Mother of God has inspired a cult?