Columbus merit is the same as that of many other brave explorers of whom most people never heard.
I myself have never considered Columbus as a Saint or Reformer, just as an explorer that by accident got to some new lands. The fact that he was the first one is what makes him notable; too bad for the other explorers that have been ignored.
All of them had one thing in common, ambition and greed. None of them including Columbus was example of human rights, as a matter of fact very few humans are.
Even today, what is the real purpose of space exploration?
$$$$$$$ and Power