I didn't read Harry's statements as stereotypically male-child-stupid or even stereotypically male-stupid, but stereotypically hyperintellectualist-male-stupid - as in specifically similar to behavior like Luke's, not that of any non-Internet non-rationalist man I've actually met. A male child of ordinary intellectual background, no matter how stupid, could not have made the specific mistakes Harry made here, because he drew his deemed-inappropriate ideas from "enlightened" papers.

A good example of stereotypically male-child-stupid is Ron's lines you quote here (and many of Ron's actions in general). These are stupid comments Ron was able to make in spite of not having read any papers.

Hermione's reactions are stereotypically female-child-stupid. She reacted the way she did precisely because of not reading these particular enlightened papers. This is the exact opposite of Harry's stupidity! I think I understand why you wrote the scene with these results - Harry has read lots of rationalist papers you think more people should read, while Hermione in spite of her intelligence does not have the exact same background. However, because Hermione's actions fit with "stupid female child" - not alleviated by her intelligence - and Harry's with "stupid-though-very-intelligent male adult" (Harry's reading on these specific psychological ideas is very incongruent with that of even most well-educated 11-year-old boys), we get subtext like Alicorn points out about female infantilism and so on.

As for some anecdata, last month when I was explaining to a progressing-to-ex-boyfriend that he did not meet my paramour standards, he said I should consider lowering my standards, and I said he was proof that strategy could not possibly work for me.