I think you're right again, but only with another limitation: concerning applications, not libraries, frameworks, or development tools. The latter function as

I think you're right again, but only with another limitation: concerning applications, not libraries, frameworks, or development tools. The latter function as components or unfinished goods, not independently usable software. The right to "use" such incomplete programs or software-production tools is meaningless to end-users. It becomes meaningful to them only when parts and tools are incorporated into, or used to build, other software. Software that often isn't open source, by anyone's definition. If the finished good is proprietary software that the creator will distribute to users, GPL is a blocker. Distributing copies of the final product will trigger GPL's copyleft conditions. If the finished good is software that its creator will run for others, as software as a service, AGPL and other network-copyleft licenses are blockers. Providing the service to users over a network will trigger requirements to provide source.