You're missing the point. The useful thing is to run some service on the LAN, be it a web interface for a NAS, a web interface to control some lighting, a web interface into a media PC to do remote desktop type stuff or control media playback, a debug interface into some embedded product I'm working on, or a whole host of other things. The thing that makes web technologies useful for this is that it Just Works, from any other machine on the LAN (my laptop, my phone, a guest's phone, etc).
By making technologies available only in a "secure context", they're blocking them out of this whole category of use cases.
By making technologies available only in a "secure context", they're blocking them out of this whole category of use cases.