People are funny. When I buy something, I expect it to be as advertised and work properly. Beyond that, it is my problem. I am loathe to return anything, even when I have a full right to.
My wife, on the other hand, will buy 8 pairs of shoes with the full expectation of taking 7 back. She says that it is too hard to make a decision at the store. She will even order online, knowing the packing and mailing process, when a vendor offers free return shipping.
Insane, to me, time, work, and fuel etc. I can't stand the hassle and the waste.
But you guys are right, I suspect that a lot of keyboards are returned after an overnight switch trial. Ugly business.