Hitler is not a helpful comparison because we are able to straightforwardly contextualize the relative terribleness of his actions with sources that are immediately comprehensible in ways that those in 1492 will never be.

What you can say without batting an eye is that Columbus took lemons and made lemonade, by which I mean he took [discovery of comparatively resource-poor islands] and turned it into [why not slavery and hierarchical over-taxation until we approximate solvency]. Genocide is not relevant because it is purposefully murderous; from all accounts, Columbus was incidentally murderous, and largely indifferent more than anything else unless it factored into the bottom line of his rather questionable business models.

So evil? I don't know. I know that he was put in chains for his conduct by his alleged constituents, but they were also somewhat self-interested in that he was the person they owed the most money, rightly or wrongly, and by and large these were not shrinking violets so much as fellow brutal men who saw him as dangerous and incompetent in terms of administering them. As pleasurable as it is to view the trends in social media as inherently fallacious, the only real error is to confuse Columbus' terribleness for something that makes him any less remarkable or important to study; whether he "deserves" a holiday is quite apart from that. Mathew Restall, in the excellent (and highly recommended) Seven Myths of the Spanish Conquest, establishes pretty comfortably the extent to which Columbus was viewed in his own time as fortunate rather than personally exceptional, and how much that colored his place in recent memory.