Personally, I think "cowboy coding" is the best derogatory name for this. IMO, what all of these ninjas have in common is that they don't realize that software development is a team exercise. Berkeley did a study on BSD and found that a file was opened 10x more often for reading that writing (i.e. people read code 10 times for every time they make a change). To my mind, "cowboy" conveys the proper amount of ignorance of the other people on your "team."