The premise of this thread is confusing. Hangar 360 is a free app, and you are not obligated to use it. Furthermore, if you do want to use it, you are not obligated to upload the photos for processing. If you are looking to retain ownership, you can either let Hangar 360 capture the photos for you and decline to upload, or purchase Autopilot and use Pano mode for similar results, but with more options for controlling the camera settings.
Is the general idea that Hangar, as a company, should be obligated to incur the development, transfer, processing, and storage costs and receive no compensation in return in the case where you opt-in to uploading the images from Hangar 360?