We don't use k8s and you don't have to either. This is for current and future users who absolutely want k8s. We are a compute provider after all and making it easy to host a great variety of apps is good for our users.
In my opinion, the concept is not trivial to grasp by oneself (meaning: is not trivial to drive into that conclusion even after reading the article). So, being explicit first, and guide the reader through that concept along the article would have made a big difference.