Did you not account for the value of the downloaded games? The buyer got a bargain.
It's not like iTunes or Kindle where you could conceivably use the files on something else. It's like my wife, who kept our DSL modem even though we got cable internet. It's like selling a car with tinted windows, buying a new car and calling up Toyota and asking them if they can tint your windows for free.
Do you normally keep games (discs, cartridges) for a system you sell? It seems bizarre not to sell the games as well.
Not bizarre at all. Steam, iTunes, XBL, and PSN do transfer content to a new device using an account system. Software and hardware are generally separate, Nintendo has been the sole exception in this newer digital age.
You provide an reasonable example with the car analogy, but that simply isnt how it works with digital content most other places.
Eidt: I should say I am cognizant of this and thus measure my Nintendo digital purchases carefully. I certainly spent a LOT less on Wii VC games as a result.