I think the point here is that games are not made for a specific gender and not made to cater to both genders either, games are made for people who like the genre/combat/gameplay etc regardless of what gender they are. Their gender doesn't enter the equation when making the game, or shouldn't, at least.
The idea of making a game for guys or for girls doesn't even make sense anyway, because everyone has different tastes for games within a gender group, as you've demonstrated with the example of your wife.
Simply not true.
Everyone has different tastes on an individualscale, but male and female brains are biologically different, and have broadly, and
noticeably different tastes when taken as a whole.
When you're talking about an audience in the millions, patterns of taste and behavior quickly emerge that undeniably skew along gender lines.
That doesn't mean there aren't individuals that buck the trend, but they're an insignificant minority as you scale up your sample size. Basically human gendered behaviour is bimodal, with the vast majority having very uniform tastes, with fewer and fewer deviating away from these norms the more divergent you go.
If you make a game for
everyone you have to take away elements that will appeal overwhelmingly to any one specific group, that is overwhelmingly not liked by others.
The easiest example for biological differences between the sexes you should be able to understand is height.
Line a hundred people, 50 men and 50 wen, up from shortest to tallest, and obviously the tallest 50 will be overwhelmingly male and shortest overwhelmingly female. That doesn't mean you can't get tall women and short men, but they're outside the norm.
The same is true for basically all human traits, including the structure of the brain and hormones, which directly influence tastes and preferences.
It's nice to imagine we're all unique individuals entirely governed by free will with limitless possibilities and universally equal and boundless potential, but the sad fact is we're all just apes, and we all have boundaries set by nature we conform to, especially on the macro scale, and gendered behavioral norms are one of those boundaries.