If it doesn't have anything to do with browser as client then why would they choose a hobbled protocol like http or websockets? MQTT, AMQP are already standards

If it doesn't have anything to do with browser as client then why would they choose a hobbled protocol like http or websockets? MQTT, AMQP are already standards for this and much better suited for nearly any task. They are more powerful, more efficient and simpler to use than http or websockets. And if you can't get past the firewall or proxy both of them will run over websockets anyway.