Thanks for all the responses! It may help to distinguish two types of speculation (cf. https://terrytao.wordpress.com/career-advice/theres-more-to-mathematics-than-rigour-and-proofs/): "pre-rigorous speculation", in which one asks "dumb" questions (cf. https://terrytao.wordpress.com/career-advice/ask-yourself-dumb-questions-and-answer-them/) before fully knowing the field, and "post-rigorous speculation", in which one shares informed insights and opinions from one's rigorous understanding of the field.

I think we should encourage both types, in appropriate venues of course (and separated from traditional "rigorous" work).

I didn’t say the Cicero paper should be rejected and I would not necessarily advocate for that.

But there is something that makes me grumpy. Science, and, more notably, Nature have become the place for big-flashy-things. Often (but not always) these big flashy things have a moderate scientific innovation and a huge engineering achievement. That’s fine. Except Science and Nature are received by a wider, more general audience that is less able to parse the nuance. This in turn drives hype cycles.