That said, all the pets I've had throw up way more than I do. I think we're ignoring the very real possibility that ancient people were constantly living with some level of gastrointestinal problems.
We do know that humanity from its earliest days over the Rome Empire [1] up to, what, maybe a century or even less ago has had massive infestations of all kinds of parasites, including gastrointestinal.
Would it be possible that these parasites actually could have a symbiotic relationship, in helping to break down spoiled food?
[1] https://www.livescience.com/53303-ancient-rome-infested-with...
By eating spoiled and contaminated food, ancient people were certainly getting internal parasites too (also something that a big fraction of pets have).
I think there's a bit of a slightly saner way to put this viewpoint-- that:
- Humans evolved in a very different environment from which we live now
- Our degree of genetic adaptation to modern living is relatively small, because there's been a blink of an eye for it to happen in
- Even if something newer has a sane rationale for it being "healthier" or "better" despite us not having genetically adapted to it, it may not be so: most of our handwaving rationale about complex systems ends up being wrong after careful trials and measurement, and the rest we may be missing a lot of second-order and third-order effects.
Not that I'm advocating for eating rotten meat. I'm just saying that the system is complicated and has a bunch of set-points learned from very different conditions.
I too don't like rejecting things outright, but knowing that, I also don't accept things outright either. We have no reason to believe that eating rotten meat wasn't a choice made out of necessity rather than out of some sort of optimal health.
First, basically every choice could be said to be made out of some kind of necessity.
There's a big middle ground even from this. E.g. "eating rotten meat caused a lot of harms, but it also happened to fulfill a couple of somewhat important functions, and thus there was no evolutionary pressure to meet these requirements in any other way"
Thus, even if eating rotten meat today would be a net negative for many, many reasons (and I strongly suspect this is the case), it makes a lot of sense to think about and study what possible benefits it could have had besides merely being available.
One time my dog and cat both ate some human food which was perfectly fine for them, but the cat didn't like the flavor. So the cat vomited. The dog looked at the cat, looked at the food, looked at the cat, and then vomited also.
Then the dog finished all the food and was fine.