You are for certain correct, there is a strong need for such a device, the only reason it doesn't exist I'm sure is because there is no way to advertise on it. This is why I funded the Pebble and Pebble Core. I anticipated the Pebble to be the next big utilitarian notification device, and the Core (headless Smartphone) to potentially inspire a new type of minimal, even colorless smartphone that you describe. Unfortunately, they ran out of money. I still use my Pebble and it is a fantastic replacement to all my notifications on my smartphone, without any of the unnecessary HD graphics.