The Spaniards weren't there to rape and plunder alone as you portray.
It was never a hit and run job. Spain was meant to stay in the New World......for good. At the time, Spain was the One World Power. The Same as Britain and France -later on- with the powers that be behind all of them.
They were there to install a new, all encompassing system of control -The Catholic Church-. And to destroy, assimilate and most of all, to create a NEW Race. Hence... Mexico was borne.
They always KNEW where the Aztec and the Mayan were before they even set sail.
And they came down on them for a very simple reason.
To bring forth the New World order. Yes it happened 500 years ago...it really is nothing new and it truly is a very old plot. You are only witnessing the last stages unraveling now where a lot of things are gonna come together at breakneck speed.
And that is all. This has been happening all along....long before you or i were even borne.