Opinion of replacing Columbus Day with Native American Day

[Okay, maybe Mike Johnson is a competent parliamentarian.]

Considering the culture that Columbus came out of, what he did was nothing short of astonishing.

It's astonishing that somebody from a Renaissance Italian seafaring culture became a sailor, managed to get funding for an expedition based on an underestimation of the size of the planet about which he consistently refused to listen to as it happened entirely correct outside opinions, then spent the rest of his life on a power trip that alienated so many of his subjects as Governor of the Indies that at one point he and his brothers were hauled back to Castile in chains for incompetence and tyranny? Actually, now that I lay it out like that, I agree with you, I'm just not astonished in a good way.

We should have a day to honor explorers in general, not one specific more-than-usually historically significant but less-than-usually admirable one.

[Okay, maybe Mike Johnson is a competent parliamentarian.]

What culture was that?

The one that by policy tortured heretics, burnt witches, made no technological advancements save armor and weapons between about the time of Heron of Alexandria and Copernicus, fought with Muslims because they thought God wanted them to, conducted an Inquisition, believed Jews were demonic, and thought the Earth was at the center of the universe.

Most of this I don't think really has to be addressed (because it's more or less true, even though the way in which you're presenting it indicates a perhaps shaky understanding of the context behind why these things were the case and even though you're unduly dismissive of what medieval society was able to accomplish in its less savory aspects' despite), but the bolded part is completely false and ridiculous.