My problem isn't who wrote it, but the pretense of something having written by a person while it wasn't.

There's something profoundly disrespectful about it towards the receiver.

Oh very much agreed. It fundamentally destroys someone's reputation when they refuse to acknowledge that Ai wrote something.

Far better, and frankly perfectly acceptable, to say or have it implied or concluded, that Ai helped with the writing in some way. Still, if you're paying attention, it often shouldnt really be all that detectable because you should be aware of AI's smells and you can edit them away. Though, sometimes I'll leave it as obvious that Ai produced something I shared - eg making a well formatted github issue or whatever. But I'll also make sure to convey that a thinking human was behind it, vetted it etc