Those people also typically want to "save the environment", but I doubt they want to save it so much, that shaving a fiver off their power bill means they get a thermostat tell them when to wash their dishes and do their laundry.
Putting the dishes and clothes in and out is still a manual activity, so this makes absolutely no sense to be scheduled by a thermostat, unless you have waaaay too much free time on your hands.
I think home automation is mostly composed of things that sound neat and provide modest utility; Nest might pay itself off faster, but most buildings would see more benefit from increased insulation. Something like programmable lighting is fantastic, but it probably isn't going to save much money or energy, and switches just aren't that burdensome. I'm glad there are people trying to figure it all out, at some point the cost might get low enough where "neat" is enough justification.
Yeah I see the potential, but even though I'm a programmer, I see a lot of random shit put together, and no clear reason why I should go through the effort of building a mental model around it in order to understand their vision.
HomeKit is just a set of APIs right now, so we have yet to see if it has legs, but it centers around a versatile device I always have with me - my smartphone. It makes far more sense to make smartphones the hub, so focus it around Android, not the thermostat...
The Google-Nest relationship is a bit toxic right now and people are all scared that their data is going to leak the Google way. But we all know it's going to happen, why delay the inevitable with this forced, confusing vision of the home?
I've seen such integrations fail before. Apple had those weird wireless iTunes / iPod / Hi-Fi integrations in the early 2000s and it never caught on, because it was damn confusing (and plugging the speaker audio cable in your iPod was way simpler).
This stuff needs to seem simple and inevitable, so people say "but of course I want that". And this is not it. It looks complex and arbitrary and their own ads videos say "people might say, why are we doing this". If you anticipate people might say that, you've failed.