This is an important principle. If essential systems in everyone's homes start depending on remote connections to work and/or including spyware that phones home

This is an important principle. If essential systems in everyone's homes start depending on remote connections to work and/or including spyware that phones home with any kind of data about how the system is being used then that's a serious security and privacy concern. It's bad enough that we have metered supplies of various utilities and instead of the old "agent pops round to read the meter every few months" we now have smart meters phoning home with metrics every few minutes. At least the metering is there for a legitimate reason and the change to smart meters does have some real advantages including for the homeowner so the risk is more an unintended but unavoidable side effect in those cases. Almost everything else that goes under the "smart home" banner seems to be like smart TVs and connected vehicles: if it's phoning home then it's a good bet it's doing it for their benefit and not yours.