Sure, but not all of us are building products at the scale of Amazon and Microsoft. When you're shipping something like DynamoDB, the argument for TLA+ is obvious. What's harder to come across are the people finding ways to make use of technologies like this on a smaller scale, and I think that's one place where Hacker News really shines as a way of connecting people.
At least personally, working at a small and understaffed startup, I'm not always going to find the time to put together big case studies on interesting things I do, but it's a lot easier to share a sentence or two on a casual Hacker News thread. I wouldn't be surprised if it's the same for other people.