Nobody answered my question.
The point behind it is, there are no universal rules regarding nationalities. As long as you don't apply double standards and stick to your law, its ok for me.
If Rossi wants to represent Italy, so be it. they didn't break any rules and he would have got the passport whether he was a good footballer or not. Whats not ok, is that Brazilan guy that plays for Poland. They gave him preferential treatment because he was a good footballer. No way could he have gotten a Polish passport in a few months if he wasnt a good footballer.