Colonists aren't us. We aren't them. We don't have to pay for their sins. It was a vastly different time back then, and the rules have changed. The same way I'm not responsible for slavery. I don't owe anyone for the sins of my (fore)fathers.
Go look at other countries immigration laws, and many of them are much worse than ours. Every civilized nation has them, and using emotional weaseling doesn't absolve people of needing to meet those requirements.