I myself rarely use the term "open source" but this does not stop others from (mis)using it. The mere fact that a term is generic does not mean that it is meaningless. If someone is genuinely unaware or confused about what the rest of the world thinks "open source" means, then I am happy to educate them. But if they are deliberately exploiting mis-use of the term to hide nefarious intent, then they can go to hell.