I'll be honest, I've gotten a lot less understanding about shipping ace/aro characters over time. I used to go "Oh people change characters sexualities all the time, so it's fine", and I still do think that, mostly.
But it's absolutely fucking maddening to watch people go "You cant ship a lesbian character with a gay character, that's erasing representation" and then turn around and ship an ace/aro character with someone. What the fuck are you talking about?? Either it's fine or it isn't, you can't have it both ways!
What this comes down to, of course, is the irritating fandom mantra of "Asexuality and aromanticism are spectrums! Some aces and aros have romantic or sexual relationships!" And of course that's true - There's a massive range of experiences under the asexual and aromantic umbrellas. But most people take it to mean "Therefore this ace/aro character can have sex/have a relationship/whatever without changing their sexuality" and... most of the time that isn't the case.
There are some canonically ace/aro characters that do have romantic or sexual relations, but the majority of them specifically don't - Most of the time if their sexuality is mentioned it's in the context of not being interested in romance/sex. So whilst yes, many irl ace/aro can be in relationships or have sex, characters that do the same are even rarer than ace/aro characters to begin with.
All this to say, I don't care if someone changes a character's sexuality for ship purposes. I might find it baffling but it's whatever - People have been doing that since the dawn of fandom. What I can't stand is the general attitude that shipping an ace/aro character isn't changing their sexuality. It almost always is, yet people don't like to acknowledge that, for some reason.
