I can see this as a critique on over-use of clustering for whether you have more than a handful of points to visualize. However, I do think this article completely misses the use case when you need to give a ballpark overview of density or counts for clusters. There are many use cases when you actually have natural clusters of points, like traffic accidents. When you zoom out, you might actually see patterns in the aggregated data.

Overall, spatial clustering is a very common strategy to understand trends. To dismiss it entirely is a bit sensational.