They sent out for the pad printing. And they had customers return keyboards (albeit not that many) due to the quality of the pad printing. So they just stopped providing the service.
Ah so it wasn't in house...that does make sense then, re: minimum quantity.
It's a shame most people wouldn't consider the keys being practically consumable to be acceptable. They're great looking keys and a couple dollars here, couple dollars there to replace keys that wear out would be acceptable, I'm sure, to the many people who do like those keys.