God forbit somebody profits from the code that you've posted publicly. It's a NET POSITIVE FOR EVERYBODY.
Copyright cuts both ways. Free Software and Open Software exist in context, and because of, copyright laws. This means that a person or a company using output from Copilot may be engaging in copyright infringement. In other words, Copilot is enabling software piracy.
I might be sympathetic to it, and even consider it mostly positive, but then if companies can use my code ignoring the license, I want to be able to Torrent their products in peace too.