Downloads doesn't mean people are using it like crazy.
True.
If you had the app installed on your iPhone or iPad, it automatically installed on your Apple TV for most users. That alone greatly inflates those download numbers.
Right, it means that a lot of people had it on their iPhone or iPad. And the subset of those who also have an Apple TV would certainly want it there as well.
Just have to subtract off the unknown number of people who had it on their iPhone/iPad but stopped using it.