Ancient spoiler: it's a plot point in a Douglas Adams novel.
I guess having the power to delete unwanted child comments would be too much, but moments like these it's a power I'd really like to have.
The question wasn't a real question. It seemed some kind of showing off. If you really want to know the answer you'd google it. If you ask in public like that it seems something else.
The comment felt like "Drugs! Rock'n'Roll! I'm Cool!" and little else. I'm not into opiates or rock'n'roll (or fake questions), so it was 100% turn-off.
Why, what value do you think the comment had?
I can't speak for the op, but I found it an interesting bit of trivia. Sure, they could have googled it, but if they had, I wouldn't know about the origins of this poem. And thanks to the replies, I now know what a 'person from Porlock' means. Reading that comment was a win for me. If the person was jostling for status (and I don't see a reason to think that), well, I still benefitted.
Something being turn-off for you is not a sound reason for advocating censorship. Also, not all the comments that are written to your posts are direct questions to You. "Fake questions" are usually known as rhetoric questions, and you surely know that. Don't you?