Of course, but I'd also argue that smart home appliances are mainly for those with some technical knowledge, especially configuring them to work together. It's actually no linger uncommon to find networking gear with these features, only that most people just use what their ISP gives them.

It's a matter of defaults - isp provided firewall/routers these days commonly come with a guest WiFi mode, and good ones even segregate that network. I can envision an iot mode that would a large minority of users could use. There's always going to be users who don't care, or don't have the technical knowledge, but recognise that stories on /r/sysadmin skew away from the "average user".