In addition to Europeans, the contemporary set I mentioned also includes

1. Arab slavers who made eunuchs of their captured (kidnapped) slaves, and

2. the Mesoamerican civilizations whose religious imperative was to keep their sacred pyramids constantly covered in flowing human blood

The corollary of your point, even if it was a fair and accurate assessment of Columbus' affairs, would be that Europeans were otherwise moral judges -- although by today's standards I'm sure you'd also condemn them just the same.

Columbus was a product of his times, as were the slavers and the natives.