The beauty of sharing things is the feedback you get from others, which then gives you validation that something you're interested in is something others are also interested in or derive value from.
When making a blog post, how else do you get this feedback? 99% of people click, read it, then move on. Quantifying how many people have read, how long they spent reading, and where they came from, is an essential part of interacting with the digital world. Without it you are flying blind.
You’re right that “trend” is the statistical term, but “hype train” is the idiom people actually use. I always try to write closer to common and simple vernacular when possible.