Why do predatory journals invite people to editorial boards?
Well, if you agreed they would not need to fear that you demand them to remove your photo and name and that you could sue them. Also, you could write "on the editorial board of…" in your CV and at some places in the world this would enable you to reduce teaching or get a raise. I think that's basically it. If this would be true, there would be some people that accept such an invitation. Not sure if this is the case, but does not seem impossible.