Because it does not market itself as such. It makes some bold claim to answer a question that's probably interesting to a lot of people follwing BRI-developments. Instead it's 'I've visited the Kazakhstan-China border and talked to a few people', but I guess that headline doesn't attract as many clicks.
EDIT: Not the GP and I don't want to claim that this is propaganda.
I don't know about you, but I react a lot differently to information presented in that format as opposed to something like this: https://www.nytimes.com/2019/01/22/business/china-foreign-po...
And that's the crux of the problem. This entertainment geopolitics is no longer confined to just places like the NYTimes magazine. It has basically blended in with all "journalism" today because it's great for engagement. In the best case scenario, the hallmarks of good journalism like informing the reader with facts and being impartial are mere afterthoughts.
Again, I think it would be really valuable to point out the facts or "spin" that the author got wrong here. Please do this if you have an issue with the article not being impartial or getting facts wrong.
That may or may not be a fair assessment, but I'm not really convinced. This is a New York Times Magazine article with flashy pictures. It's entertainment for people who are interested in geopolitics. It's not Ben Mauk's fault that he's an American and his piece shot to the front page of Hacker News.
What I think you're looking for is a really good Wikipedia article or research study on BRI.
Unless you can expand on why this piece is "propaganda" or what exactly the article got wrong, why not enjoy the piece (or not) as a travel diary with the BRI as a broad geopolitical context?