LG Releases Open-Sourced Version of webOS in Hopes To Push It Beyond TVs and Smart Refrigerators (theverge.com)
LG has released an open-sourced version of webOS that's freely available to anyone that wants to download and poke around the code. From a report: The release of webOS Open Source Edition is meant to act as a catalyst to drive further adoption of webOS beyond LG televisions, smart refrigerators, and the occasional never-to-be-released smartwatch. So, devices like webOS tablets and set-top boxes as pictured in the LG-supplied image above. This is the second time an open-source version of webOS has been released, the first coming under the failed tenure of HP back in 2011. LG's cross-town rival Samsung develops and uses the open-sourced Tizen operating system on a variety of devices including smartwatches, televisions, Blu-ray players, and robotic vacuums.
You're confusing "smart appliance" with "manufacturer's internet/cloud-connected appliance."
The problem isn't that the device is smart. Smart in this context just means it knows what it's doing, or what is going on around it, or what it's supposed to do.
The problem is that the devices as typically implemented today are taking your data outside your LAN to the manufacturer and any other entity the manufacturer shares it with, while at the same time exposing a considerably wider attack surface to the black hats.
Every device you listed there could benefit you via local integration with home control software.
Every device you listed there has zero good reason to go outside your LAN - you could be contacting a safe server on your LAN from the WAN to see what they're up to, should you want/need to do that, rather than channeling everything through the manufacturer's servers (which also brings a near-certainty of lost support at some random time based on their finances and product cycles.) Or you could keep all interaction with them within the LAN, which is the minimum attack surface choice, and, I would suggest, the sane choice.
I've fallen off your lawn, and I can't get up.