Actually this is not true.
The Italian system enables the independence of prosecutors, which then enables the possibility to sentence financial and political elite.
Bare in mind that a person with financial and political power and connections of Berlusconi (and public support, he can still win 30% with some tv propaganda!!!) in most other countries would never get charged... Italy is one of rare remaining countries that manages to prosecute its elite...
If a judge is corrupt (or simply makes a mistake) there is a way to repeat the trial after the prosecution appeal... This is not necessarily a bad feature. On the contrary, in Italy it is one of the crucial instruments in a fight against mafias, since those often tend to corrupt judges.