Let me say what irritates me about this comment.

It is generally well known that the eager new parents tend to overthink everything and overdo everything they can think of (stroller type? formula vs breast milk? daycare amenities? nursery wall color?).

Nice strawman here. What exactly was your probability estimate that LW readers with kids are going to discuss the rational nursery wall color?

As mentioned in the discussion and in the quoted book, there is only so much a parent can do to affect the way their offspring grow up.

Assuming this is true, there is still a question how much exactly is the "only so much". It could be still significant, and might be worth doing anyway.

It turns out that optimal parenting is not that hard.

Well, this needs a better argument than just a link to a book on Amazon. For the beginning, any argument would be better than none.

Yes, children get genes from their parents, so any hypothesis of "parents do X and that's why their children do Y" gets an alternative explanation "parents and children share a gene G; it causes parents to do X, and it causes children to do Y". It is good to be suspicious about the first explanation. But also about the second one.

For example, if the "parenting quality waterline" would actually very low, such as 99% of parents doing it wrong and getting random (that also includes very good) results, and 1% parents doing it right and getting mostly great results, it probably would not show in most statistics. Why? Simply, if the author of the research does not know what is the thing that those 1% are doing right, they would just split the sample along some other, mostly irrelevant axis... and then get the result that really, that axis is mostly irrelevant. (More generally, a difference between A and B will appear strongly if you divide people to A group and B group, and will be hidden if you divide people to groups containing a similar ratios of A to B.) The confusion would be to equate the "parental role" with what was being measured.

Provide a happy, supportive and occasionally challenging environment, make time to enjoy the little ones and don't sweat the minutiae.

Couldn't a LW group for parents help with this? It is not supposed to be a group for Straw Vulcans.

I am not sure if I am not reading between the lines too much right now, but it seems to me like a connotation "thinking about something too rationally = being obsessive and spending a lot of time (for diminishing returns)". Well, ain't necessarily so. We can also speak rationally about saving time. About making a smart decision once, and then following it. (Which could be better than deciding every time again and also better than acting on the whim.)

If you find parenting not fun, you are doing it wrong.

And the group for LW parents will make is less fun, or...?

Sorry, that whole argument did not contain much more information than "guys, that topic is boring, shut up". The downvotes were well-deserved.