The fact you don't do it means you actually don't care at all about your privacy. It takes 5 minutes to bring every member in an household in the living room or kitchen and assist them to change the wifi password on their device.
You can even prepare for it by printing the details + qrcode beforehand.
Connecting to a wifi network is one of those things every terminally connected non tech savy people are able to do these days.
I think the GP more meant the practice that some ISPs have of shipping default routers that may or may not be able to be replaced with a separate SSID that is publicly available for use by other customers of that ISP.
Not "my network has a default or empty password, I can't make people sign in again."
Is that really a thing? My ISP gives me a router that takes an SSID/password by default (that it gets back to if I reset to defaults) but I can change it any time as well as other parameters (like channels, wether WPS is activated, etc).
