I, too, have had a couple of issues with buying lenses that had "small cleaning marks" and creative lighting that hid the ugly truth.

If someone tried to sell me a camera with a lens that had "defects in the coating" I would be suspicious that these defects were caused by overzealous cleaning, and therefore there might be scratches the seller isn't telling me about. I'm aware aggressive cleaning isn't the only cause of coating issues, but it would raise a red flag.

It still might be worth something to somebody, just not to me