The original comment was about turning lights on and off. You implied FIND is better than motion detectors at this ("your solution creates more problems than FIND..."). In most cases this is false, due to the negatives I outlined above.
I think the confusion here is there's two different use cases for turning lights on and off.
I have acknowledged in another post that motion detectors are advantageous if you're dealing with strangers and/or situations where there's lots of movement and/or lights that can be automatically timed out. eg public spaces halls, public restrooms, security lights, etc. But I don't think it's fair to lump these in the same category as "home automation".
Home automation is a little more of a complex problem as you need the lights in the room to not only turn on when someone enters, but also turn off when they leave. Motion detectors can spot someone moving in a room but they're not to great at detecting when people have left since it's the same sensor that would be triggered. They're also not great at detecting if people have entered a room and are still in the room if those people have stopped moving (eg they are watching TV) - since those people aren't triggering the motion detection. And lastly, motion detection isn't great at detecting the number of people in a room - which matters if you don't want the lights to turn off when someone leaves the room but other people are still in there and watching TV.
Motion detection solved some of the problems of home automation, but creates some problems as well. Which is why I said motion detection is just too simplistic of a solution for home automation despite it being a great solution for other types of automating lighting.
Granted you could place more sensors, network them up, and have a centralised unit logging movement. That would likely work. But then it quickly becomes as complex as the solutions we're trying to avoid.
However even if all these things were easily addressed, motion detection still has issues for me personally as I have two cats. This is the beauty of proper home automation systems: they give you the granularity to personalise things so pets don't set off the same triggers that people do. Or my two year old doesn't trigger the same automation that my wife and I do (eg unlocking the front door). This is where I think the future of home automation lies and is what really gets me excited.
So you're right that there is overlap between motion triggers lights and home automation; but the latter is intentionally a more complex problem by design.
