I think the overarching point is that if you look closely enough at anyone you will find the dirt, but some people are just plain filthy with it. Sounds like they may have stretched some truths regarding the opportunity costs of introducing gold and the fact that disease wasn't an intentional weapon (to begin with) but still, making people wear their own cut-off hand if they don't bring you gold is seriously messed up stuff. Also, the buying and selling of 9 year old girls...?
Sounds like Bartolome has some dirt and Columbus has mounds of it.
As for revoking the holiday, I've always seen it more as a day to celebrate the beginning of what would become "the new world" and not a celebration of Colombus' life. I realize "the new world" has mounds of it's own dirt, still I'm happy to take the day off from work.