Maybe one use
Have a swimming pool pump that gets switched on for a few hours a day during winter, on for longer during summer. At 750watts, the cost is not insignificant to run for hours but the cost of not running it would be ending up with 55k litres of algae.
Currently use a cheap digital timer that has a UI that makes me very reluctant to change anything.. and I do have a degree in computer science. But does turn the pump off/on with a fixed schedule.
So something with a simple API I could play with in my spare time, I could see some use for.. add sensor data or a feed of data like weather or sunlight hours and the pump could get turned off an on as required.
But like the review... I just can't see the point of most home automation until there are open cheap systems that allow people to tinker away and find stuff that really works and is useful.