Not sure, it could be just Nintendo has better made stuff. I heard of ppl flushing down Game Boy games and then getting it out and still having the save files and everything intact cept the sticker....
My copy of Shaman King went through the washing machine yesterday and it still works perfectly, saved game and all. My Nintendo still works perfectly after 17 years! You were right, Bill Gates is the devil and X-boxes are unholy demons.