Only the travel from Spain to America was a considerable risk, compound that with a vast uncharted territory full of bizarre empires and only certain kind of people were willing to take the odds.

Of course not everyone was the same, but they were the exception. If you want to read something more positive and inspiring look for Cabeza de Vaca or Bartolome de las Casas for example. They tried to improve indigenous people's rights, or at least enforce the existing law, which gave them some protection but was ignored.