>Why is Crystal popping up so much on HN

1) Because HN is a social news website, so when someone reads a post about a subject, others are reminded of it, and can post in return. This happens with all popular topics, they come in batches.

2) Because Crystal is getting more popular (e.g. it jumped TIOBE rank for what it's worth), and more people like to read and hence vote such articles.

3) There's a huge conspiracy, with marketing shills and aliens, for an OSS language.

4) More than Go or Rust or React or Ruby back in the day?

Take your pick

Because Ruby is a really nice language to write code in (minus some quirks) and everyone would love a language with similar programmer experience, but much faster.

> why do all these comments read like advertisements

Enthusiastic users of new programming languages with small communities, generally want more people to use it as well, so that the community will grow and 1. produce more libraries; 2. produce more tutorials and other resources; 3. have more people for them to talk to about the language.

Because advertising Crystal means a chance for Ruby enthusiasts and some beginners to try a statically-typed language without having too much learning curve.