Don't knock the movement...
...knock the implementation.
From what I understand (and I could be smoking crack here - you'd have to ask my mother, who is something of an authority on All Things Mexican) the Church has been a major social instrument for social, political and economic change all throughout Central and South America, which is why you keep hearing these stories about murdered priests and nuns all over the place - they're awfully inconvenient for the local dictators.
Now, if you wonder what it would have been like had the Conquistadores not shown up, well, just imagine a Mexico ruled by a bloodthirsty empire that performed mass ritual sacrifice (supposedly over 10,000 in a day one time - and that's by archeological evidence, not Conquistadore myth...), cannibalism, and wars for the sake of wars. The Aztecs were not what one would call enlightened... In the sense that they were extremely brutal to their fellow humans.
