It is extremely useful for an onion address to just define a plain old TCP socket, rather than imply HTTP. An onion address is just that... an anonymous connect

It is extremely useful for an onion address to just define a plain old TCP socket, rather than imply HTTP. An onion address is just that... an anonymous connection to some server, somewhere in the world. While you might be unaware of where the service is operated from, it could be the exact opposite: maybe you just started an ssh server on your desktop and would like to access it remotely where ssh might be monitored or blocked -- despite ssh itself being encrypted, making a connection and the lifespan of the connection tell quite a lot about your habits. Or maybe you decide to visit China for a weekend... Hell, or maybe you're buried behind multiple NATs/firewalls and just need an easy way to poke from the outside (I've done this, in corporate environments where you can run your own VMs and such)