TL;DR but from the summary it says "Socially acquired" which seems like a leap to me. Couldn't it also be as simple as children don't fully understand all the difference between themelves and animals. For example, my 3 year old probably thinks dogs can talk and pilot helicopters.
With all of the Diseny movies that show animals acting like humans && knowing how kids love to watch movies on infinite loop, it's not really hard to imagine why
I often wonder to what degree frequent early exposure to humanoid animals is doing some kind of damage to people's social cognition. I think there's plenty of evidence to be had online that it's doing pretty significant damage to at least some people. But I wonder if it's also behind widespread harmful social effects like the concept of "fur babies".
Now that's a rabbit hole of a theory. Just like with anything, a "stable" person can live in a world with this kind of make believe and enjoy the story telling devices being used. However, someone less "stable" that can be less able to make these distinctions. Does that mean we all can't have it because of a small number of people? If that's the case, then I would apply this same rule to any and all social media. Clearly, some people can't handle it, so nobody can use it.