If you're trying to compare the entire concept of human violence to the very well-defined and narrow concept of caste discrimination, you're not going to get very far I don't think. And for the record, caste politics rears its ugly head in the Desi community in my country of Canada all the time, yet somehow we've managed to avoid the ugliness of gun violence and slavery that you somehow found relevant.

It makes for uninteresting discussion of the misgivings of different countries when the first thing you're able to reach for is "well what about colonialism?"

I agree that it's uninteresting!

It's mainly meant as an illustration of the OP's "We never wanted Problem X, take it back to your country!" argument, which is simplistic and uninteresting.

I'm sorry, but slavery and racism existed in America long before the Europeans arrived.

Slavery and racism existed in America before Europeans. You're right about the guns.