It's not just about your % though.
the way i see it, it's not ball-hogging if it goes in. and last time i checked, melo has a higher FG%. kobe may average more points but, how many shots does he have to miss before he gets to 25?
When a player (Melo) gets the ball and all he thinks about is shooting that's ball hogging. When your assists average is that bad, doesn't help your case as a non-ballhog either.
Melo takes some ridiculously bad shot attempts. The fact that he makes most of them, doesn't mean that he made the correct decision. He freezes Knicks' offense so many times as when he takes the ball he goes for the iso play.
And btw, Melo started the season red hot, but as we go more into the season, his %s go down and down.
MJ was probably a ball hog as well at times. Although, he not only was arguably the GOAT scorer, but he was passing the ball as well and his decision making was on another level. Ball hogging is not always bad - it just depends on more things than just FG%.