People are very hesitant to buy new appliances/home products. The last major change to the American home was the television, and that was ~50 years ago. Desktops had their day, but have been largely replaced by Laptops/Smartphones for many consumers. Adoption of new home appliances and technologies is glacially slow.
Also newer electronics have shown they need replaced/upgraded every 2-5 years. You are going to be hard pressed to sell the idea that the consumer needs to replace all their light switches and smoke detectors even every 10 years. I barely replace light bulbs at that rate now.
Cars about the only place where the IoT call home paradigm works. They are complicated machines that need semi regular maintenance. Placing sensors all over it makes sense. Trading updates for telemetry is attractive because a cars computer needs updates like any other computer. But I don't need a fridge that senses when I am low on milk, when I can just as easily look inside it and tell for myself.
EDIT: I think I should clarify that home IoT is a fad. Having machines feed back telemetry is useful, especially commercial machines with a service contract. The data is useful when its actionable. Data for the sake of data in the home is a waste.