The Suns are doubling Kobe more, so he's passing more. The Suns think Artest can't shoot so they cheat off of him. When the Suns weren't playing zone, the Lakers could pass inside to Bynum and Gasol, and they would cheat to the inside with little effect. But with the zone, the Lakers offensive flow is disrupted, they can't get anything easy. So the Lakers do what they do when they are under stress, rely on Kobe more.
He's capable of playing the point to a certain degree, but it's not an ideal situation for a team to rely on one player to be their primary scorer and distributor.