Because those were paid to victims that actually suffered, not their families (except in the case the victim died), grandchildren, or in this case great-great-great grandchildren. No benefit, except perhaps the relinquishing of land to Native Americans has been a "benefit in perpetuity" like they are demanding for "justice".
These are "equality of outcome" marxist handouts. Simple as that. This has gone from "police should kill less black people" to "let's give minorities special housing privileges, special job privileges, special speaking privileges, and special education privileges". These arent "reparations" because they aren't repairing anything. They are the systematic dismantling of the equality of opportunity that currently exists and replacing it with a neo-marxist "equalizer" that will just create two different castes of people and significantly more inequality. The only reason it's seen as okay is because in the current era this type of inequality is seen as "justice". Don't believe me that it's dismantling equality of opportunity?
Check out this article on "Whiteness" from the Smithsonian. An eminent educational firm. Equality of opportunity and "rugged individualism", according to them, is a symptom of "whiteness".
Any argument for these reparations is an argument for neomarxism. When they're done with this, they'll go after everyone else. First "white people", then it'll be Asians, then it'll be jews. It has been this way since time immemorial. They will not stop until everyone they hate suffers. This is how marxism and far-left totalitarianism works, and why it's the leading cause of death in nearly every country that has adopted communism.
South Africa tried. We saw how well that worked.