I tend to agree that we might as well make everything free. It's easier and has less downsides for society. The one place I can really see an argument for non-free software is art. However, it is possible that trademarks and author moral rights are enough to deal with that issue. So the software would be free, but you can limit who participates in the "official" version. It might suck for someone to rebrand/fork your work and claim it as their own, making no reference to the original. I believe the GPL and moral rights in most countries allow that scenario.