You mean I only need to look back 35 years to a professional medical device built when computer control was still very new and that wasn't intended to be operated by unskilled consumers, and wasn't certified by to be safe for home use?
Therac's often used as the "canonical" example, but there are more recent issues that stem from a lack of a physical interlock:
- VW's dieselgate (although that was intentional)
- Virgin Galactic VSS Enterprise crash
(yes, designed for a skilled operator, but still: no interlock on the brake)
- Pyranha Moulding's industrial oven [1]
- Hotpoint tumble-dryers catching fire [2]
Even without network connectivity, household products still get recalled for issues such as fire risk, because they lack things like thermal cutoffs, or the cutoff is in some way inadequate.
Perhaps 35 years ago computer control was still very new, but right now, IoT is very new, so there's a whole new world of mistakes to learn from, and the evidence is very clear: serious mistakes are being made.