That’s exactly it, developing a high-end plug-ins is very expensive; to give that away for free is completely illogical. It’s a restaurant giving away sandwiches and selling napkins. Selling “service” and “support” or “hosting,” is ridiculous for the plugin industry. Most people in the business know how to use most of the important plugins already, so what kind of support would be needed at a level that users would pay? In all of my 15+ years of owning Waves audio plugins, I have not once contacted their support. If I need a reverb, I pay someone for a reverb. I am not going to pay someone to provide “support” for my reverb. I’m a pro, I don’t need to pay for help with a tool that has been almost industry standard for years.
I love open source, Postgres, Rails, Sidekiq for example. But the GPL-religious side of open source? Not so much. It seems too culty-dogmatic-restricted. Kind of the opposite of “free.” “You are free to do anything you want, except anything we don’t want you to do. The MIT license is the one that is actually free.