[dugidugout]

Because validity doesn't depend on meaning. Take the classic example: "What is north of the North Pole?". This is a valid phrasing of a question, but is meaningless without extra context about spherical geometry. The trick question in reference is similar in that its intended meaning is contained entirely in the LLM output.

[simondotau]

There's nothing syntactically meaningless about wanting your car washed.

[dugidugout]

I wasn't under the impression anyone was discussing car washing.