Of course Luca wants Vettel, he is still a child and thus can be manipulated. He has thrown at least 3 temper tantrums this year alone i can think of.
1. complaining to the team to do something because he couldn't get past the much slower Button.
2. complaining because he got a drive through for running Alonso of the track and Italy
3. crying that Karthikeyan didn't jump out of his way and that's why Hamilton got by in Austin
Hamilton has matured a lot since last year, and is becoming more and more like Alonso, in that he is not afraid to criticize his team for short comings.
I love the way you draw your conclusion from a few radio snippets that we get to hear. Do you seriously believe there is not similar conversations going on between the other drivers and their teams?