OK, this sounds reasonable. In my case, there was a single broken key on the keyboard (either the cap or the scissor was broken, I ended up replacing both with

OK, this sounds reasonable. In my case, there was a single broken key on the keyboard (either the cap or the scissor was broken, I ended up replacing both with a used key from ebay), and the Apple authorized service provider told me they could only replace the whole keyboard. Good to hear that this is not an actual Apple policy, because it seems ridiculous.