Let's look at some of the aspect of life described in the article. Assume I'm just some artisan, good at my job, respected for my ability to work materials into goods. Making the odd innovation here and there. As a result I'm not in the ruling elite, nor the warrior "caste", but I'm doing pretty good for myself compared to most people.
Basically let's just say I'm equivalent to a decent software developer in our society.
I can imagine all sorts of things:
* I'm ashamed that I'm not a member of the fighting classes
* I don't have strong opinions of that fact
* I have a strange (to me in the 21st century USA) relationship with those of the fighting classes
* similar thoughts toward ruling elites, plus:
- Do i worship them or revile them? Do I have differing opinions on different people in that class, or do I view them as an undifferentiated mass?
- Do I expect to have any influence, or none, etc? How do I feel either way? (I can imagine having influence on the noble class but being rather upset because they are supposed to have a direct line to the gods, and why are they asking me?)
Other things I can imagine:
* Do I fear being sacrificed? Am I ashamed if I am afraid of it?
* Do I see the sacrifices as great? Or do I see them as an unfortunately necessary unpleasantry? Or do I see them as a source of shame because the rulers are out of touch? Is there an apocryphal tradition of the Gods actually being gentle and not wanting blood sacrifice, but this is being ignored by the priests?
* If my kid gets recruited to the military, am I proud or scared or both? Do I prefer his capture or his death in battle? What conduct makes me proud or not?
Basically my point here is that imagination and lack of data combined results in a truly honest answer of "I don't know which of the options for any of the questions above is right". This leads to a simple "I don't know", not because I can't fathom it for lack of empathy or imagination, but because I can see many many different ways it could be experienced.
Think of the gazillion different, mutually incompatible attitudes that modern Americans have about Hillary, Trump, and everyone else. Now re-imagine your artisan. You can be simultaneously afraid of being sacrificed and ashamed of being afraid. You might have a great deal of respect for some of the warriors but also revile the way they lick the elite's ass. You might have heard that the next village got leveled and all of their women and children enslaved because they dared to question the authority of the high priests, and have conflicting thoughts about whether they deserved it or not. Your friends might disagree with you on this matter, but some of them are afraid to speak out. But then this big customer wants his swords repaired by morning, and you don't have time to worry about those things anymore. Most of daily life is mundane, it has always been. Just because there are human sacrifices going on on that hill over there doesn't make life unrecognizable all of a sudden.
Knowledge of specific details is not a prerequisite for empathizing with someone as a human being. The point is to appreciate the many different ways that a Mexica life could be experienced (which you do very well) and keeping it all in your working memory instead of aggressively map-reducing it into answerless questions like "What did the artisans think about the warriors?" Likely, there were more than one artisan and more than one warrior.
Failure to imagine what it's like to be someone else, from a different place, a different time, with different ways of thinking -- is perhaps the biggest reason why we have so much violence and hatred in this world, and modern scholars are just as guilty of it as warmongers and propagandists of the past have been.
It is a failure of imagination, a failure of empathy, that every culture encourages -- sometimes subtly, but often not so subtly -- in order to keep its members loyal. One of the defining characteristics of human cultures is that each wants to have a monopoly on a person's mind.
Most of us grow up believing that their way of thinking and living is the only natural way, and parents and teachers rarely try to give us a world view that goes beyond what's considered mainstream in our own cultures. Having lived in a cultural greenhouse all of our lives, the first thing we do when faced with a radically different way of life is how different this other person is. The differences so overwhelm us that we forget to appreciate our common humanity, with all its greatness and weaknesses, that should be the first step towards truly putting ourselves in the other person's shoes.
It would seem that anthropologists and archeologists are no exception.
Is it repugnant to kill innocent children at the altar of some imaginary being? Of course it is. Is it a necessary trait of civilized people that they cannot bear to imagine themselves growing up in a culture that practices human sacrifice as a matter of course and learning to participate in the bloody rituals? No, it isn't. It's just a failure of imagination that our own culture encourages. We have learned to be unable to imagine ourselves performing such terrible things, just like Victorian culture made it look normal for young women to faint at the slightest sight of anything disturbing. The inability to "fathom" another culture, no matter how seemingly barbaric, is not so much evidence of the moral depravity of the other culture as it is a testimony to our own narrow-mindedness.