Commercial-grade applications need some grade of offline operativity that classic HATEOAS can't provide, often target users who won't learn or can't really use a web browser (tabs, back button, extensions, bookmarks besides whatever they can fit in the bar, etc), often want to give a UX which abuses and deforms a web browser by design.
Yeah, FE engineers may all look like dumbasses with macbooks (i don't think this of them!), but they have real problems to solve.
That's for sure, for example any blog software (a few SSGs included) is a failure for WWW and for itself (most of the interaction between author and reader must be mediated with third-party or big cloud to avoid spam and scam).
