If you buy a product you should be able to use it even if you completely break all ties with the original vendor. Otherwise it's a service and not a product.
While I'd happily support regulating tethering as well, because it'd certainly make some things easier, with a little bit of thought you can build out home automation where it's all under your control. E.g. stick to zigbee and z-wave devices as the default, and get dumb zigbee and z-wave USB dongles, and connect them to an open source bridge, like Home Assistant, and you've got a good start.