Specifically, I liked it because there's a huge number of opinions on programming languages and (as the author notes) people ranting against other people's opinions on programming languages. I think it's very valuable to say: I understand the ecosystem of opinions on programming languages and purport to be above that.

You know he's not serious when he says it is the best language (the word 'opinionated' is even in the HN title, though not the article itself?), but you know it means that he's trying to go beyond bickering over functional vs imperative, typed vs untyped, etc. It got my attention and started me out with a good impression.

It.. somewhat delivered. I don't know Prolog, which makes it harder to decide. Some of the opinions are very reasonable and reflect awareness of language-advocate-bickering (for example I agree that 'optional typing' is the only defensible way to handle types if you are trying to unify lots of preferences on languages). But non-deterministic variables, while cool, look like black magic to me and I can't judge their good-vs-bad-ness from this article.