If you overturn every single conviction that involves a bent cop, then you will in all likelihood free both the innocent and the guilty. It the principle of ""It is better that ten guilty persons escape than that one innocent suffer"
An "unsafe" conviction is not the same as proof positive of innocence, just no longer meeting the necessary standard of proof. It may be necessary to overturn a number of convictions but isn't easy.
You seem angry, I'm absolutely not trying to apologize for this behaviour. But it is a mess, and the consequences of the mess ought to be severe so that it doesn't happen.