Balotelli's issue is he isn't a team player, he's immature, and his movements are bad. His talent is out of this world, but his brain is tiny. I own a Balotelli jersey, but I'm pretty much done with him.
The following characteristics of Balotelli are detrimental and will always make me prefer a guy like Destro as a #9 over him.
1.He is undisciplined and takes really bad fouls at inopportune times. Marchisio's tackle was bad, but you could argue it was accidental. Balotelli's you can usually chalk up to him losing his head for a moment.
2. He has personality issues. Whether it is laziness in training, indiscipline off the field, or he is just saying something very childish on Twitter it is clear he lacks professionalism. Legends like Del Piero and Totti were professionals.
3. He is an inherently selfish player. He'll always take the FK with Milan even if another has an opportunity from a better position (ie: Honda with his rocket of a left foot coming from the right side).
4. He lacks discipline with his positioning. If he isn't happy with his service, he will drop deep into the midfield and disrupt other players movements. He is not a false-9 and does not have the playmaking abilities to drop deep like one. It just confuses the attack.
5. His behaviour causes others to get agitated with him. Ultimately a unified team is most important, through wins and losses. If guys like DDR and Buffon are openly criticizing him post match, it may suggest he was acting like an ass.
For me Destro is what the Azzurri need. He is a no nonsense striker with the highest strike rate in Serie A. He is quick, smart, and can score with both his head and feet. If the right support cast is there, he will finish his chances. He certainly will not do as Balotelli does and try to take matters into his own hands by becoming a central midfielder. He may not score a goal from 30 yards, but ultimately those goals are rare and I'd take a guy who plays in position over one who doesn't 100% of the time.
And even if Destro said something stupid when asked whether he wants to be a reserve, he deserves another chance. Balotelli has had dozens. If Destro shows the same error in judgment repeatedly then he shouldn't play either.