Thank you, I just don’t like anime
That’s a bit like saying you don’t like Italian cinema. It may well be true but I tend to doubt you’ve seen enough of it to really say that. That’s also not what you got in trouble with your ex for saying. You called her interests stupid.
They’re not stupid. I’m not a fan of Beavis and Butthead either but I wouldn’t tell someone who is that the show is stupid, no matter our romantic relationship or lack thereof. It’s rude and (in this case) cruel.
and I’m very blunt
You keep saying that like it’s an immutable fact about yourself. It certainly isn’t.
If there’s something about her watching the show that’s legitimately bothering you (example: playing things you hate at talking volume or higher while you’re around), you should have had that conversation.
If it’s just the fact that someone enjoys something you don’t … that’s a really unpleasant attitude to be around.
Up until this part, I really wondered why you felt the need to tell her about the unrealistic nature of her goals.
I don’t think you would be the asshole (provided, you know, you put it in a reasonable way). It does seem like she’s trying to get something out of you that you’re unable to give.
Since she keeps pressing, I think I’d deflect. “It’s more important what you think you can accomplish. I’d love to hear your plans for accomplishing them.”