I would suggest the Catholic Church has gone positively wacky with Mary. Even the Orthodox roll their eyes over the Marian doctrine that has been coming out of the Church for the last 200 years. People are seeing Mary more often (thousands of reported sightings yearly) simply because Mary is hip.
It was very poor form for the Spainards to run into Central America to loot and plunder at the same time they were trying to convert the lost souls. However I sincerely doubt that Mary was, or would have been, more appealing to the people than the word of God. God's word, after all, is the power of salvation and the method by which He instills faith. Visions of Mary, while they make make everyone feel good, just doesn't have that type of power.
Be careful not to set up a false dichotomy here. Mary, pregnant, is carrying Jesus, the Word of God. Pretty clearly this is a package deal, not an either/or.
And if you go to the Basilica of Guadalupe (or any other Catholic church) you can't help but notice that the Mass is drenched with Scripture: not only the Epistle, the Old Testament lesson, the Psalm, and the Gospel at EVERY Sunday Mass, but in fact all the prayers are either straight Scripture or based on Scripture.
So if Mary got them into the Church, she got them into the Word.
You certainly don’t believe, “For God so loved the world, that He sent a book...”?
Do you really think that insulting language like this accomplishes anything, or wins anyone to your point of view?
I just looked at "The Cult of the Virgin Mary" by Michael Carroll and on page 183 he states;
"The greatest stumbling block to anyone searching for the psychological origins of the Tepeyac apparitions is the fact that there are no accounts of these apparitions that date from the period of the apparitions themselves. There are, for instance, no references to any apparitions occurring at Tepeyac in the writings of Bishop Zumarraga, even though he was supposed to have been a central participant in the drama."
If this is accurate it would seem that the "need" for these apparitions superceeds objective analysis.