Last time I've seen similar reasoning, it was when a person was attacking the term FGM (female genital mutilation) on the basis that it is "colonialist misjudgment of a different culture".
We can, but it is pointless (the culture is now dead and gone) and it does raise questions about objective and absolute morality, of which many people disagree.
It also can easily lead into very messy discussion about modern day actions which in some sub cultures (and other cultures that may one day exist) would look equally horrendous. For example, we often are fine with abortion because of our standard as to at what point a human counts as a human. How can one objectively say our standard is okay, but someone whose standard is to not start counting til a year old isn't?
Or to bring up another hot button issue, look at MGM and the differences in how it is treated compared to FGM. You can barely even mention these concepts without risking a flame war (that is still a term, isn't it... feels like I never hear anyone use it anymore).
So what disturbs me is how accepted MGM is. And how those who criticize it are dismissed as crazies. That's exactly the situation for FGM in societies where it's the norm.
And again, FGM is undoubtedly a far^N more serious issue. And I support efforts to pressure and educate societies that practice it. Just as I supported efforts to end apartheid in South Africa. Or slavery in northern Africa, India, etc.
For a comparison, murdering someone is very very different than punching them, but we still making punching your toddler illegal even though we agree it isn't nearly as bad as murdering your toddler.
So things that are very very different can still be quite illegal if they are horrible enough, so why doesn't that apply to those cases? It all comes down to subjective and often illogical judgments made by a society.
You know what they say: those who do not learn from history are doomed to repeat it. This necessitates the moral judgments, as well.
> It also can easily lead into very messy discussion about modern day actions
All discussions about ethical philosophy end up that way. But, again, such discussions kinda need to be had for us to evolve. I understand that it's simply out of scope for, say, archaeologists, and I don't expect to find moral assessments in their work. But I also don't see why it's wrong for the rest of us to apply them in a completely different context.
> But the Mexica would not have seen death when they looked at the tzompantli. They would have seen life.