I would think that hikers who assumably appreciate nature and etc would understand that they need to be responsible and do their part to preserve the beauty of whitney.
I agree that you cant police what people put in the bag or if they use their bag or not. But if a hiker is issued a bar coded bag and that bag does not show up as bar coded into the trail head deposit station then that hiker could get a fine. That would at least be a way to keep the bags from being left on the mountain. Kind of like red box works.......terd box.

These people that hurt the environment undoubtedly cause increased fees and quotas.