I suspect any savvy writer will try to write to their audience, and when the intended audience is evenly split among genders they'll find a way to write to both genders. Not just gender - they'll find ways to craft a complex story with elements that appeal to a wide range of readers, along multiple demographic lines. (Sometimes the intended audience will be a narrow demographic, however.)
In a further discussion, he also said that male readers like a hero that they can look up to you, while female readers prefer a hero who is an ordinary person and more human.
In Star Wars, Rey is an awesome hero.
(1) She is 'ordinary and more human' in the sense that she is struggling to survive and 'the man' Unkar Plutt is sticking it to her. She also ... just wants her family. It drives her. She misses her parents. (Like HP does.)
(2) But, she is also someone 'to look up to' - She has the force, and is supercool with technical gadgets; she can fly the millennium falcon and do repairs on the drive while it's in warp. Without ever having seen its insides before! Awesome!
The writers push both sets buttons that your friend identified. She is normal and awesome.
Personal experience: Within my real life critique groups, if I share an excerpt for critique: It is more typical for those that I presume self-identify as male to focus on technical and hierarchical details, and for those I presume self-identify as female to focus on personal and interpersonal details. The correlation is far from absolute, but (sorry), it's present, in my limited experience. Whether that's indicative of a larger problem or not is a different discussion.
Additionally, in my dual hero story, the male readers tend to identify with the male protagonist, and the female readers tend to identify with the female protagonist. (Tend to. It is not absolute.) The male readers have asked me why the heroes aren't more kick-ass. The female readers have asked me what their motivations are. A few female readers have also told me to stop being so mean to my characters. Male readers have not made this comment! Again, not absolute.
Bias is a tricky thing. I suspect we all want 'all of the above,' but that doesn't preclude an age bias, a race bias, a gender bias, a class bias, other biases that we may carry as readers and are unaware of.
As far as evidence, there's data on gender bias in genre authorships and readerships at the link.
None of this stands in opposition to your position that women and men enjoy the same stories - we do - but it does pertain to the idea of what women and men gravitate towards and enjoy. A good writer will find a way to meet many needs.