Right; but in the case of a stereo receiver (or any TV-connected devices), the IoT model makes sense: this is a device you interact with on a regular basis. There is already an ecosystem of devices that support things like Bluetooth, AirPlay, etc. so when your receiver has them, it's actually kind of useful.

I've always thought that the reason for keeping Android as open source was to enable this use case. Eventually, Android-capable SOCs will come down to a very low price point, and for these use cases they don't need to push much more than a few kb per second. But it retains the advantage of having a development ecosystem that is well understood and widely available (you can't throw a rock in China or India without hitting an Android developer).