They are jerks, kidnapping Sarah to have sex against her will for the purpose of breeding.
How would the Bajorans retcon this into being something grand.. it would be like the holy spirit impregnates unwed teenager deal. At least Mary got two millennia of veneration for her trouble. Sarah had to flee to Australia (typical) and then got killed off. They did not care about their precious vessel one bit, she had all the value of a jam jar.
And if you read the actual dialogue between Mary and the angel in the Bible, Mary is actually asked and gives clear consent of her own will, before the Holy Spirit impregnates her. If the writers of DS9 meant to parallel that, then they clearly forgot that verrrry important part of the equation. It indeed makes the Prophets either amoral in the literal sense or actually having an evil streak.