Wow! You have replied to a thread which is two years old. 
A lot of stuff has changed in that time. Trust me: this is a very active forum, you will always be able to find a newer thread unless it is an FAQ in The FAQ section, in which case it will have been updated frequently.
Please donāt resurrect the threads that are this old unless you know that thatās the only one with the information, it just confuses everybody.
So, letās start over. 
The ecobee sensors are only intended for use in controlling the thermostat and Have a weird algorithm and a very slow reporting interval, so you just arenāt going to be able to use them for use cases requiring more frequent reporting. So nobody is using them for regular motion sensors. ( less frequent reporting means a longer battery life, so itās quite common with specialty sensors that they have long āsleepā intervals.)
You can read more about motion sensors which are being used in the device class features thread: ( The topic title is a clickable link)
Although the FAQ thread was started a couple of years ago, you can tell from the last post in the thread that it does get updated frequently.