Well, of course, it's also in part a business decision. But it's also in part a technical decision, because you cannot directly reach the home devices from outs

Well, of course, it's also in part a business decision. But it's also in part a technical decision, because you cannot directly reach the home devices from outside the network, so you need a "cloud service" anyway if you want to allow the user to control their devices remotely (and you don't want to deal with the mess to set up that is port forwardings). With IPv6, your device has a global address, so the user can just use a web browser to control the device from anywhere on the planet without any need for port forwarding, that is what IPv4 with NAT prevents.