[jjav]

> Posting on a blog saying that people 'SHOULD' do something

To be fair, it's not about some rando on a blog post. The HTTP response codes and their semantics are in the RFCs. And while it's true the RFCs say SHOULD and not MUST, there are also now ~30 decades of experience and expectation that a non-existent resource is more likely a 404 not 200.

Sure a server can always do what it likes but can't expect it to play well with the outside world if it goes against both convention and documentation.