Why?
Because it did not happen as you have postulated.
The Catholic Church didn't enslave Latin America any more than the Baptist Church enslaved the American South.
Latinos turn to Catholicism because they believe it is true.
The catholic church didn't directly enslave the people, but obviously turned a blind eye to it or was in direct approval that it take place. Why can the populace of these countries NOT see that? The catholic church with all of its influence could have said, "This is wrong. Stop it."
Oh, but it DID happen as history states it happened. The Spanish (strict catholics) enslaved the people of Latin America for some 300 years (exactly 300 in Mexico). One of their priests, Miguel Hidalgo, started the revolution in Mexico against that practice and other oppression of the people. He was executed after a CATHOLIC tribunal. Now, answer the question without obfuscating or lying.