Yeah, but those greaves are a part of a still existing culture and religion/beliefs, I don't think it's the case with the ancient Egypt, Vikings graves etc
in the U.S we have the Native American Graves Protection and Repatriation Act (NAGPRA), passed in 1990, requires museums and federal agencies to return Native American human remains and cultural items to their tribes. It’s all about respecting Indigenous heritage by ensuring that these items are returned to their rightful communities.
If you had actually ASKED the Sioux of the Black Hills about this, you'd know they've told pretty much everyone "yeah we don't like Mt Rushmore, we don't like Crazy Horse's relief carving either, but we think destroying them is more disrespectful than just leaving them to fall apart on their own." Like, this isn't an uncommon thought. It's just more complex than "blow them up".