It is a bit of a catch-22, a plain english wrapper opens up the tool to be more widely used by novices, but also prevents those novices from actually learning the tool.

Not really, how are they prevented from using the manual or the copious amounts of examples out there?

Memorising command line options beyond the absolute basics has rarely been helpful to me. And I use FreeBSD, where arcane commands are plentiful.

Nothing, but after becoming reliant on an LLM they may simply become overwhelmed and give up once they outgrow it's capabilities. I've seen this happen to several people I know.

It's not so much being down on the work, as it is being down on 30 years of keyboard junkies proclaiming "Plain English" interfaces.