Preferring Biological Children Is Immoral

Reminds of Daniel Everett's work with the Pirahã, who have non-existent recursion in language. Unfortunately one exception in biology is not evidence of generality. Proof by contradiction works in math, doesn't work very well in biology. Doesn't even work well in physics e.g. room temperature super conductors are extremely rare even if they exist.

Physically you can make people do anything, but what they want internally is a completely different matter and there is no way today to probe that.

Let's assume there is a large section of people who can only love their direct off springs, the author could perhaps claim that that would be immoral - is this gaslighting or what. What's the end game for this kind of stuff - it's to eliminate all preferences - quite akin to slavery.

This is a prime example of why people dislike philosophers.

It's like they take a perverse pleasure from pissing in peoples' cornflakes.