Being downvoted for this comment so many times is a small example of PG's essay, "What You Can't Say."
Anyway, there's some schools of thought which consider religion to be a necessary evil for pre-scientific organisation, so I'm sure enlightened future scholars will be studying religion's phases from its medieval heyday through to its current last hurrahs with interest.
It was probably a bit offtopic, I"ll give you that. I was raised in a very religious family that has negatively impacted my life in a few ways. I guess I see the damage of religion in more places than most.
But inflammatory? I think that's the point of the PG essay I referenced: that just saying something "you can't say" automatically makes it inflammatory. The statement's truth is irrelevant.
"Your comment annoyed me also for its obviousness and vague smugness"
For someone who has a lot of very religious friends, I don't think this is obvious to many people. I hope I'd have the standard to not write something that is so obvious as to not benefit the majority of my readers.
We may imagine that we are a great deal smarter and more virtuous than past generations, but the more history you read, the less likely this seems.... I suspect the only taboos that are more than taboos are the ones that are universal, or nearly so. Murder for example. But any idea that's considered harmless in a significant percentage of times and places, and yet is taboo in ours, is a good candidate for something we're mistaken about.
To make it clear: thinking particular taboos are caused by religion is shortsighted. These things keep happening over & over again, and unfortunately "progress" isn't always towards something you may like.
However, human sacrifice (aka murder) is a taboo that is shared by many cultures. That makes that different to the other things you lists.