It sounded like a moral argument to me, but I'll take your word for it that you're making a factual claim about the law. What law exactly says that they "they bore some responsibility" for other people's copyright violation?

As an example, the federal murder-for-hire law is what specifically establishes legal culpability for your not-quite-analogous example: https://www.law.cornell.edu/uscode/text/18/1958