Yes, obviously there are legitimate uses. That’s not the point. The point is the actual codebase of YouTube-dl features copyright infringement as a test case. RIAA is using this to make the case that the tool is designed to aid in copyright infringement.
That seems like a reasonable argument given the evidence and the DMCA. I’m not defending the DMCA or RIAA here.
Does any camera manufacturer showing a camera filming a live concert in some promotional video needs to worry?