[Buckterrier]

Because it's painted. And I'm not being a smart ass. More & more interiors are painted vs. in mold coatings. On top of that non paintable plastics are being painted, (because they're cheaper, yes cheaper vs. less expensive). By that I mean plastics that require adhesion promoters. Skimp on that coating, (even though it only takes .1 - .2 mils), and you've got trouble. Paint companies at the OEM level are required to pass very stringent specifications. Even a sweat spec. Paint companies make artificial sweat with various acids and other components to mimic a person's sweaty ass hands. The stuff smells friggin' horrible. And of course there are DFT, (dry film thickness), requirements. Low film builds can also be a culprit.
Bottom line, it's not the coating.