I don't think Kobe is an elite stopper, either, I just said LeBron has the skill and size to be one.
As for Kobe's defense, it's ranges from pretty good to great, depending on his intensity. The thing we have to remember is that it's impossible to play at that high a level of offense and play all out defense at the same time. It just drains you too much. People seem to forget that Jordan eased off on defense when he had to take over the scoring load. Pippen was the primary stopper on that team.
Kobe CAN be a great defender when he asserts himself, but it's nearly impossible to ask someone to be the best perimeter offensive and defensive player. When he goes full tilt he's better than someone like Raja Bell who only has to worry about threes and defense.