I agree with the OP and have the same request. It is NOT crazy (well, not very crazy) to wish to use wireless connection with a headless server, mainly because of the existence and rapid improvement of CC (Calibre Companion) on android devices. I want to do this, using a headless very low power Dreamplug machine (running debian GNU/Linux) which I'm content to leave running 24/7.
The point is that Calibre already includes excellent command line commands and options for this sort of use. For example, if I use the command calibre-server on my little linux box, the calibre server is started, and I can use one of my (e-)readers to browse the OPDS catalogue and read or download books from the linux machine. And I can lave the content server running all the time if I wish.
What the OP and I want to know is, whether there is a command line command to start the wireless device connection server in a similar way, and if so, what it is.
As an aside, I could in the past run the calibre GUI from the linux machine by connecting in with ssh -X (allowing X forwarding) from eg a laptop. For some reason (probably my fault), this doesn't seem to be working in my current configuration; and besides, it's much less use than a command line method, because one would have to keep the laptop running to keep continual availability of the wireless device connection.
I hope my explanations reveal how much I value Calibre, and my hopes for Calibre Companion. Many thanks to all involved in these great projects.