I woke up this morning at 6; my Nest (Google product) thermostat was programmed to dial the temperature up from 55 to 65 at 6:30. I reached for my phone and the app wouldn't connect to the Internet. Gmail also stopped updating.
There have been a few discussions over on a home automation forum I frequent, talking about the perils of depending on a cloud, or worse, C2C ("cloud to cloud") solution for anything as important as heating your house.
I get that it's far easier for the manufacturer to do everything on their end, so they don't have to worry about supporting whatever local install you have. And I've seen C2C solutions which are so easy to set up, you hardly know you're depending on your hardware, two other companies' hardware, and all the networking in between.
Then there's the risk that the manufacturer will declare your hardware obsolete after a few years (or in some cases, months) and shut down the servers. Or that all the personal data they collect will be sold to (or hacked by) organizations you'd rather not give that information to.