To be honest, apps and plugins that get abandoned are one prime reason we need a way to sensibly obtain the files to fix issues ourselves if we want. I know many wont have the skills to do that but as someone who has patched abandoned plugins for vbulletin for years I think we as customers of plugins should have some ability to get plugins manually.
We are customers, pirates will always find a way to do what they want and they arent all lost sales but causing issues for customers will lead to lost sales. Always think of those that are prepared to pay over the concerns of those that would never pay.