Then they've been fucked since C beat Lisp, and that hasn't been enough to cause Silicon Valley to implode.
That is a completely different argument.
No it's not. If "bad software delivered faster" is a problem, it's a problem long before LLMs. But the history of software-based products has shown that "delivered faster" is consistently more important, as bad software that attains significant usage will be made into good software one way or another.
I'm not skeptical of the idea that LLMs will be useful tools to cost-effetively develop high-quality software. I am, however, skeptical that the input to these LLMs will remain mostly informal and conversational.