We rarely have more than a handful of DNFs in big events... I guess people here just love to play! Why would you travel so far, only to drop after the 3rd or 4th round?
The only reason I dropped was because I didn't want to be in the top cut. I was fairly sure I wasn't going to be in there, since I got downpaired twice, but IF I somehow ended up in the top cut, I wouldn't be able to play it, because I had to travel back with a group of youngsters I was responsible for.