Without the ease for proprietary software development Rust wouldn't get as popular nor it would receive the same support from big tech. Without that popular support it wouldn't be as performant, nor it would attract the top system programmers it did.
It is also extremely naive to think that copyleft licenses aren't actively violated. It is rampant and at this point violating them is the industry standard actually. Making software effectively "ownerless" by accepting many independent developers makes it also equally hard to defend its licenses. The socioeconomic system of the West prioritizes private ownership. Without a clear private owner (or a consortium acting on behalf), it is hard to defend GPL and the rights.
I’m personally completely fine(legally not morally) with people or organizations who want to keep trade secrets secret, but not if they also want society to protect anyone copying their work. The tradeoff is you show society how to accomplish your innovation and we’ll guarantee you profits for X years with the might of law
Edit: this was in response to the comment about no one should be compelled to share their work. I don’t know enough about the nuances of copyleft vs permissive licenses to have useful commentary