I think if you want to understand bigotry against aromantics, I have a good case study. Let me talk a little about my dad's family.
My dad has 4 half siblings and two step siblings. They're all a decent bit younger than him. When I was a teenager, we went to a family reunion, and I realized something—my dad did not respect his siblings. He looked down on all of them. He saw them as fuck-ups and overgrown children. My dad had the American dream: well paying management job, suburban house, wife, and three kids. My aunt and uncles did not. Excluding my aunt, none of them were married or in serious relationships. They hadn't really settled into long term careers. Several of them were working the kind of jobs that get called "Unskilled labor." So he looked down on them because the youngest one was in his thirties (and several were much older), and yet none of them had "settled down" into what he saw as lifelong, permanent careers and relationships and lives. He was polite to their faces, sure, but I heard how he talked about them behind their backs, to my mother.
And then a few years ago, we visited his brothers again for Thanksgiving. And I realized something again--he respected them now. He saw them as equals. Why? Well. All of a sudden, every single one of them had serious, committed romantic partners. They didn't even need to still be with those partners—one of my uncle's fiance passed away from cancer before they could marry—just having had one showed that they matured into a real adult participating in society. In fact, at one point, my aunt was telling my mom about how one of my uncles was no longer living in an apartment she owned, but instead, after having a steady girlfriend for about a year, he moved in with her. And my mom literally said to my aunt, "wow. Look at that. He finally grew up."
One of the lines that frequently gets repeated about anti-aspec sentiment is "why would anyone hate asexuals/aromantics/etc? They aren't even doing anything." And that's exactly it. In the eyes of amatonormative culture, we aren't doing anything. Adults are supposed to do things. That's how you become a member of society.
I know that my father will never see me as a successful adult. He will never approve of my life. And I think most people would assume that that's because I'm trans. And don't get me wrong, he sure as shit doesn't like or respect that, but I do think if given enough time, he would get used to it. He would eventually realize that it isn't going away. And if I settled down with a spouse and a respectful job and a few kids, he could see me as a successful adult that he could be proud of anyway. But of course, that's not going to happen. Because I'm aromantic. So I'm never going to do that one thing that signifies that his job is complete, and I'm officially a full-fledged adult. I will perpetually be that fuck-up kid who won't settle down. In my personal case, that's okay. My dad is a conservative piece of shit, and if he doesn't approve of you, that just means you're doing something right. But on a societal level? This kind of attitude is a massive problem. Aromantics deserve to be treated like adults, and to feel like the accomplished adults that they are. We should feel like we belong in society.
