I know it's just a contest and a lot of the problems are made up but I really worry about things like this. Judging from the number of people with performance questions on this site and the folks/problems I run into in real life, there are enough people that don't understand how bad all-in-one queries can be.

I liked (haven't been there in a while) Phil Factor's "Speed Phreak" challenges a lot better. They allowed folks to use some very effective "Divide-n-Conquer" methods.