I wasn't clear: it is going to hurt the part where people are supposed to share their designs and innovate on others designs and have a vibrant community of content creators enjoying freedom in a wide pool of work. What is going to happen with the CC-BY is that most companies are not going to share their work, because they don't have to. What is valuable about Open Gaming isn't just that everyone gets to make 5E books -- it is that everyone gets to share in everyone else's work and in remixing generate something new.
But that's not on WoTC. Nor is it a feature of the OGL- after all, they don't have to put any of the remix in the OGC, do they? They can just, um, Monte Cook it.
Same here. If you don't trust 3PPs to release their material, well, then they won't. But that's not a WoTC issue, is it?