They don't corner-cut or take shortcuts (although they will pit you at any opportunity).
They understand the basics of driving, i.e., stay on the road most of the time. They have no ego to feed, don't care about accumulating points, or any other such nonsense that drives otherwise intelligent people completely clinically insane.
They finish their races, unless they somehow get stuck on something - or simply forget how to reverse after ramming grill-first into a wall.
Finally - and most importantly - if they're going to lose, they don't wait until you're twenty-five yards from the finish before dropping out of the race.
I will occasionally still do online matches... but in reality, it seems like a total waste of time - even if you win you're frequently docked points.
Karl Childers could have created better OMP for RR3 than this disaster.
J.