The "rightly" in your statement is simply a function of who has political power. For example, I doubt many people who dug up Native Americans' parents got locked up. Also, once your parents' grandchildren or maybe great grandchildren pass away, there is little chance anyone will care about digging them up, especially if the land is in demand.
I think generally you're right. OP has a point, but at the end of the day, as social beings we all play a collaboration game. This involves sometimes doing things or forgoing doing things that we have no interest in because others have an interest they want respected. In exchange, we expect respect for our interests, even when others don't share that interest.
If OP doesn't care about human remains, there's nothing wrong about that. However, others do care about how remains are treated. in exchange for care about whatever OP does hold sacred or in honor, OP ought to show care about human remains, despite being disinterested.
The first link you posted 404d for me, but I read the second PDF to largely agrees with me and OP actually that it is the interests of the currently living people we actually care about. To be clear, I'm one of them.
