Another way of looking at it is - software is not very different than ebooks. Imagine if an author of a book says “Books should only be sold as subscription. It’s almost as if my readers don’t want me to feed my family!” If every reader is not continuously paying me $5/month, how can I keep learning and providing little updates to this book, and make errata?! How dare they try to get my knowledge at once when they can be paying me so much more to keep me fed?!