All the keys are wearing hats, so the switches should be fine. Probably needs a couple of drain holes and some acrylic spray over the circuitry. 2¢ per keyboard.

Problem is, then they sell 40% less keyboards.

If instead they thin down the metal in the switches ever so slightly, then they break 2 months after the warranty expires and they sell 40% more...

Not just cost, but typically some volume/mass as well. For a keyboard I think there'd be some sacrifice in "key feel".