I don't understand this mindset.
HTTP was a protocol designed for transferring text files. It literally means 'HyperText Transfer Protocol'. Its use case has been getting broader and broader over time. Why does everyone want it to be a silver bullet? There are no silver bullets. Jack of all trades, master of none. WebSockets is great because it's a separate protocol and can be dealt independently by browser and server vendors as security and functional requirement change.
HTTP was never designed for pub/sub... How does the additional layer of complexity provided by HTTP for file transfers (e.g. request headers with each request, response headers, cookies sent in each request, mime types, etc...) benefit us for the pub/sub use case? It just adds overhead and makes it harder for vendors to fully implement HTTP. What used to be a simple protocol is becoming prohibitively complicated.
HTTP was never designed for pub/sub... How does the additional layer of complexity provided by HTTP for file transfers (e.g. request headers with each request, response headers, cookies sent in each request, mime types, etc...) benefit us for the pub/sub use case? It just adds overhead and makes it harder for vendors to fully implement HTTP. What used to be a simple protocol is becoming prohibitively complicated.