This take is baffling to me when I see it repeated. It's like saying why should people use Windows if Bill Gates did not write every line of it himself. We won't be able to see into Bill's mind. Why should you read a book if they couldn't bother to write it properly and have an editor come in and fix things.
The main purpose of a creative work is not seeing intimately into the creator's mind. And the idea that it is only people who don't care who use LLMs is wrong.