1: Cultural barrier - Japan is really fucking strange, there are some oddities that are endearing but others, not so much. For example the strange pedo-culture that is just ingrained in the anime community, the fucking panty vending machines, idol culture, there are so many strange creepy weird aspects that I simply can't relate to. So when I see gratuitous panty shots of underage girls or "500 year old demon lolis" I just feel disgust, and you can chalk that up to simple western puritism but you can't lie to yourself and say that it isn't a permanent part of the anime legacy. I don't like watching things that make me think of the creators obsession with young girls, or their autistic interpretation of a highschool love, simple as.
2: Translation: Anime doesn't translate well, at all. Even if it's a really good anime, the dub will always be mediocre to bad, because most of the time very little effort is put into the dubs. Again this is personal experience but subs are annoying to read, they strain your eyes, especially when you have to read them during a flashy action scene. This could specifically be a "boomer" issue though.
3: Sometimes you just don't feel like looking deeper. Think of like a one-hit wonder song you really like, and then ask yourself if you ever bothered to listen to any of their other music. The chances are you haven't, it doesn't even have to be a one-hit wonder, sometimes you just really like a song but you don't care to look into the bands other music, you might click on one of their other songs and skip through it trying to find the same feeling. But this is an inevitable failure because you are expecting it to be the same as the thing you liked, but that just isn't the case. Akira could just be the one-hit wonder anime for Vin. Of course it could also be a "guilty pleasure", like a song that you listen to from a band you hate.