Why not get a wildcard certifiate for you domain and then put the local services in internal-only subdomains ?
Do you also expect a regular end-user to install their own electrical outlets ?
The internet is just too important to leave to amateurs, look at how much damage badly configured home networks and computers are causing already. This stuff needs to be secured properly.
You also didn't need a drivers license when cars just became available, but now there are shitloads of cars we have to make sure drivers are capable before letting them drive. Same goes for network-connected equipment.
That way people are then motivated to hire a professional. Also, people making devices will be motivated to not use a default "admin" password because customers will start saying "uh, this smart toaster cost me hundreds of dollars when I plugged it in."
A ridiculous proposition given the current state of technology? Also yes.
If it happens, implemented in turnkey devices (such as SOHO routers) in a way that enhances vendor control rather than empowering home users with the option to use their own domain names and certs? Likely, that's the trend these days and doesn't show signs of receding.
The last line is kinda a tangent, but if that came to be the case, I would no longer be on board with the idea every device should have a FQDN.