In short, a demonstration of commitment.

I have similar feelings about getting AI-generated "communications" from people (email, whatsapp, whatever).

The value of having a human send me a message is that there is also a signal in there - the human at least understands what whey they sent me. They may misunderstand the concept, they may be mostly inarticulate, they may in fact be altogether wrong, but at least I know what they think, and I know when to ask them for clarification.

When a message is sent from an AI, I have no idea if the human doing the copy-and-paste even understands what they are sending me. The signal that they understand the contents of the message, that signal is missing.

It's no different to asking someone a question, and them pasting parts of a manpage as their entire response: I can't tell if they understood what they sent me.