Ah, so Apple is linking the feature of finding _my_ phone with reporting on lots of others? That explains why people turn it on, but I find that creepy.
The technology is also built so that the location is encrypted for the device owner - so Apple doesn't have a database of the location of every Apple Find My enabled device in the world, which for me makes it not creepy - my devices can find my devices.
It's really useful for locating lost headphones, laptops, etc. -- whether stolen, left on public transport/taxi, or left at a friend's house.
Is there any independent analysis of this end to end encryption of location data, that confirms that Apple can not really access the location even if they want to?
Most of users want a way to find / lock / remotely wipe their 1000$ phone in case it gets lost or stolen.