Rust compiler error output certainly uses a lot of vertical arrows. But it also highlights the fact that the caret is often used to highlight characters on the line above, and if it were lower it would be worse at doing that.

I do hate this asymmetry when I'm trying to do an ASCII flowchart of some sort.

But I'd also like to add that calling it an unreasonable complaint sounds a little hysterical. It's just a complaint. It's also a clear one, and of obvious use.