Agreed. Plus if it truly downloads all of that every time, something has gone wrong with caching.

Overeager warming/precomputation of resources on page load (rather than on use) can be a culprit as well.

Relying on cache to cover up a 15MB JavaScript load is a serious crutch.

Oh totally, but - normal caching behavior would lead to different results than reported in the article. It would impact cold-start scenarios, not every page load. So something else is up.