Perception is a funny thing. That's the cool thing about modern sports though. We now have people that follow every game and look at every play and every shot. So no longer do we have to rely on the few images that stick in the mind to pass judgment on a player's performance.
I'm sorry, but your argument has no basis in reality. Its been created and molded by the media and its fascination with the 10 second highlight. Kobe has had some great moments, and some that were not so great. As has Lebron. But there is no comparison, in the regular or post season, to their performance in the clutch. Kobe takes more shots than anyone in the league but he doesn't make many of them. Lebron is one of the few players that plays better in the clutch, takes fewer jumpers, collects more rebounds, blocks more shots, and creates more turnovers.
The first is the main difference between the two. Kobe takes jumpers....generally long and fading away from the basket. Lebron bullies his way to the hoop. One is a horribly inefficient method of scoring, the other is one of the more effective means of putting the ball in the basket.
Lebron doesn't do enough bullying his way to the hoop in big games as he often settles for jumpers.
If lebron had played well in the clutch he'd have a title by now or at the very least another finals app or two.