> Would "hello world in 100 languages" be worthy of a blog post?

Yeah. Because a blog post is just an outlet for somebody to write. There's no minimum benchmark that needs to be met to be "worthy" of writing a blog post. What a stupid way to look at the world.

> It is mildly interesting, but in my opinion, not worth a blog post from anyone more experienced than a college student.

Again with the worthiness. I have a suggestion: if posts like this are uninteresting to you... don't engage with them?

> I think that learning the syntax of a language well enough to solve one day of AoC is a dubious achievement. You don't learn the language well enough (in my opinion that takes at least several weeks with the language), you don't even get a head start if you were to later start a project in that language, since you saved a few hours at best. The only thing you get, is to brag about it in a blog post. But who are you trying to impress?

So what I'm learning here is that you not only have a terrible outlook on the concept of blog posts in general, but you didn't even actually read the blog post at hand.

The post isn't about the syntax of languages, nor is it about the author's efforts to learn the languages whatsoever. It's about his high-level approaches for planning to solve a known set of problems using a variety of languages. The specifics of the individual languages are unimportant for this sort of post.

I also think it's weird that you think this sort of thing requires a target audience to be "impressed". Again, I think you have a wholly terrible outlook on what blogs are for. People read Matt's blog for his perspective on things. He doesn't need to "impress" anybody, nor is he trying to.

> There's lots of platforms that were build around competitive programming, (starting with Topcoder, Codeforces and many others). Everyone is excited about AoC, but very few people spend time on those other platforms for fun.

Again, an advent calendar is a regular event that many people participate in for fun. The scope of the challenge is well-known in advance, it's a long-but-not-too-long commitment (25 days), and it's a cultural thing to take part in with other people. It also doesn't focus on optimization; it's just whether you solve the problem. Advent of Code also has their leaderboard feature such that individual communities can run their own AoC competitions, which maybe encourages some people to participate (but also does not alienate those who don't wish to compete against other people, since they can just choose to do AoC on their own).

Competitive programming tends to focus on optimization, requires a lot more study and effort, does not occur as part of a regular cultural phenomenon, and so on. They're wholly different endeavors. I don't think there's any mystery to it at all.

> Competitive programming problems are just as fun if not more so.

To you. Some people like that AoC is simple. It gives them something to do. It's like having a one-a-day sudoku calendar on your desk.

> Nobody would write the "25 algorithmic problems in 25 days" blog post.

I don't see why they wouldn't. I think that would be an interesting post. If you're so into competitive programming, why not be the person to write such a post? Or do you only complain about other people's creative endeavors without contributing your own?

> In my opinion, most people are excited about AoC because those problems are not too difficult, and anyone can solve a few problems at the start.

What's interesting to me about the way you've phrased this is that you're talking about enjoying not-too-difficult problems like it's an inherently bad thing. I think this says a lot about you.