I think you are coming into it not considering their perspective in a glaringly obvious way. As someone who was gaming in the mid 90s on, I legit, legit, had no female gaming friend or even knew any girls who didn't think gaming was weird or dumb or later in life around high school would make fun of you for playing with a child's toys. It was not until I moved to the US and went to college that I would meet any normal gaming girls, and by then I was online enough to not be surprised by that. Now, my disposition generally is to just be above petty interpersonal grievances, so instead of taking it out on them or growing bitter, I just pitied them for being ignorant of the awesomeness of gaming, it wasn't just girls mind you, boys also had this facade of "growing out of gaming" thing going at that age, though they secretly would play em and just lie about it which I actually took way bigger issue with.
But yes, if at that age group with that background you came over in the early 00s and claimed you played games, and not only that, but you played in the same way I did, I would look at you like I was seeing an alien riding on a unicorn. Not because I hate anything about it, but just out of sheer incredulity borne out of a lifetime of counterexamples.
Now, some people are less magnanimous and let these lifetime worth of experiences get to them, they grow bitter and hateful, and they approach this issue with "well, if you're gonna call me weird and immature, screw you and everyone like you". I don't think it's odd. This is legit a lifetime of bullying manifesting here. I think expecting kids to be as mature as an adult is an unreasonable standard.
You need to stop thinking about you and think about what experiences drove that person to be the way they are. If you think they're just automatically evil and sociopaths then you are doing the same thing they do when they treat girls like the enemy because they were being met with scorn for just having a hobby just like you were.