Apart from the fact that it isn't always the best sorting algorithm and it's pathological worst case is in fact as bad as a bubble sort's worst case (O(n^2) with a higher base operational cost, as at least bubble sort's worst case is somewhat cache friendly). This happens in three cases; 1) all the elements are sorted in descending order, 2) all the elements are sorted in ascending order, or 3) a special case of 1) and 2) combined, all the elements are equal.

Because its quick, right?

It also sorts.

Also: It has a cool name. It's much better than 'slowsort'