It's the "Age of the Geek," as Alec Hardison would say. He's a hacker on a TV series that ended four years ago, but his words are no less true.
In many ways, most people are geeks, expressing their deep interest in a particular film, television show, band, hobby, or sport. They are not just comic-collecting, bespectacled nerds brandishing a wand at a moment's notice. The world is full of geeks, and many of these geeks engage directly and enthusiastically with popular culture.
Pop culture is usually viewed as something silly, fun, and not worth thinking about too deeply. Tell that to the sports fan with countless stats memorized, or the budding musician who spends hours practicing their favorite band's songs. Fans of the "geekier" side of geekdom—genre-specific films, shows, and books—often express their interest by writing and creating art based on it, but some also engage with it through critiques of the shows and movies they love.
Unfortunately, critiques of big names in pop culture are invariably met with someone saying, "Why are you complaining about this? It's fiction! It's not real! It doesn't matter!"
Fiction—be it fantasy, science fiction, horror, superheroes, or any genre bringing the unreal to the page or screen—tells us something incredible about the things that are important to us as human beings. It matters, not just to the fantasy and sci fi geeks, but to everyone who reads and watches and engages with these fictional portrayals.
Rowling writes about wizards and dragons and magic. She also writes about a boy growing up in a role he never asked to be in, joining a new school, and navigating a culture that's unknown to him. How many people have been the new kid at school? How many have had to deal with the expectations of adults around them?
Representation matters. Pop culture matters. Because even in a world of magic, superheroes, aliens, or ghosts, the characters are based on our understanding of humanity, and there's no way to write a story or make a movie without consumers looking for themselves and learning about life. When a piece of pop culture deliberately ignores a group, or dismisses a population's experiences or identity, it is a reflection of the world we live in.