There may well be people learning the language, and this tutorial series is suited for people who do not have access to your code reviews (which, I’d venture, is the vast majority of the population).
If you think it is a stretch that people use force unwrapping I respectfully disagree. I’ve seen code in large corporations and startups, even using Swift 5.1 where such habits are prevalent. Your experience and code presented in your reviews may differ, and that’s great! Not all experiences are the same!
This article is for people that need this type of concrete example for these principles, and who perhaps don’t have access to people to guide them through.
SwiftLint enforces a coding style but there is, in my opinion, value in knowing why, and when I began coding I’d have loved a guide like the one I’ve produced. Now there are plenty of tutorials and guides out there, but I feel many have few examples and are poorly written without a tight structure. I’ve tried to create something of high quality, and I see a need from speaking to people and working in the industry and despite your feedback I’ve decided to keep creating them.
If you need a guide about installing SwiftLint there are plenty that exist — for example https://medium.com/developerinsider/how-to-use-swiftlint-with-xcode-to-enforce-swift-style-and-conventions-368e49e910.