What are they exploiting? Are they violating the terms of the license? The point of OSS is that there aren't arbitrary restrictions to its use; you can do what

What are they exploiting? Are they violating the terms of the license? The point of OSS is that there aren't arbitrary restrictions to its use; you can do what you like with it and the open source maintainer has absolutely zero obligations to continue supporting the software, or implement any of your requests.