Carmelo is not a chucker, he operates on the post. He wasn't allowed down there in the spread PnR offense, he was relegated to perimeter shots....so he took them.
The moping and **** was stupid, but it's not like he broke the offense by shooting...that was his role.
He broke the offense when he posted up...like he's made a living doing...and then he either didn't get the ball, or when he did, there was no movement off the ball because everyone stood around watching him like "what? wait...but I'm supposed to...what are you...."
Would have made more sense calling some plays for him down there, or not waiting 41 games to run some 2-man game between Melo and Amar'e.
Notice how MDA always "tries new things" when he's in jeopardy. Bout to be fired? Lets try Lin. Things getting tense in NYC and the organization, job in jeopardy again? Lets run a pick-and-roll between Carmelo and Amar'e....see how that works out...yea...
As a head coach, he needs to see these things long before the "**** it, why not?" period.