Also, we're not talking about personal code either, but something that is arguably a product humanity, or a part thereof, would want to preserve for posterity.
Lastly, no one is telling you to open anything. I am saying that if someone decides something you have created need to be preserved, they should go ahead. You can protest, you can sue, the point is it shouldn't stop anyone from trying. Which doesn't apply to this case, as the owner of Winamp actually wanted to make it open source.