That's a fair criticism of Ray Allen, but out of all of them, he is the purest shooter available, and he has been there before.
Manu is certainly a much more active player on both ends, but for some reason, I just don't see him as an All-Star. I do like his game very much though- he's very disruptive to other team's defense. Maybe if I saw his play more often, I'd give him the nod.
Jason Terry is also a reasonable choice, and he might have an average equal to Allen's if he didn't have to share the ball with Stackhouse, Howard and Nowitsky. But he came up very small in the playoffs last year with Miami when it counted the most, so I don't see him as being worthy of being an All-Star.