I remember seeing the differences in painting techniques out on the South Dakota Sacred Appliance Burial Grounds. The all porcelain cabinets were dirty, but usually cleaned up like new. The baked enamel (paint) were usually the absolute worst but this varied from brand to brand but the best of the painted cabinets were the Maytags - color and shine would fade but there usually was little if any rust on them. I didn't know that about cars, it's interesting how many different methods all the different manufacturers have tried through the years but still...rust, rust, rust!
I don't know why SQ/Amana machines tried this, I see it on Whirlpool DD machines with painted tops as well. Bleach is so corrosive, it doesn't help matters much when sloppy users don't take care of drips and spills right away either.