I've compiled many apps using API 22 for months. These apps not ranked, not even got 1000 downloads. When I've changed API to the new with new permission system, suddenly my apps starting to getting downloads.
My friends have similar issues so I think apps compiled with older API are filtered somehow in Play Store. I understand it that older API is just dangerous for users and Google want to eliminate older permission system.
So it's time to get used to API 23+ and new permission system.