Another suggestion
It could also be a new way of introducing obsolescence into a product. We all know that anything can be made to last almost a lifetime, regardless of how much it costs or where it's made. That is a fact. But of course manufacturers cannot afford to do that, as a good deal less consumers would continue to buy new goods if their old one carried on working. So they build in failure when designing a new product.
But with failure comes customer disappointment and the potential to boycott that brand. Why did my appliance go wrong so soon? Will I buy that name again? And so on & so forth.
But now a new form of obsolescence is creeping in. A variety which doesn't cause the appliance to break down, but one which does make the appliance look rather scruffy, yet the blame doesn't get passed to the manufacturer, but still the fashion-conscious consumer begins to hanker for a new appliance. In this instance it is the see-through parts which scratch and discolor, or even just get dirty.
Other examples: metal kettles & toasters in a range of bright, fashionable colours, all painted in a way which will scratch very easily, when the user clips the appliance against walls and working surfaces, and of course around the switches, especially if the female user has long nails.
Washing machines, with their instructions written in poor quality ink, on the front of the soap-drawer, this being the one part which gets the most amount of cleaning and thus the letters fall off.
Irons, telephones, and remote controls, where again the numbers are printed in such a way that they soon wear off with use.
Many people might think twice about blaming the manufacturer for this, rather perhaps thinking it was their own fault. It's a very clever strategy.
(I think)
