Criminals were corrupting cops and politicians long before Prohibition, and they continued to do so long after Prohibition.
A tiger is a tiger, and tigers do what tigers do (to steal from Rush Limbaugh). The same is true with criminals. They commit crimes. It's what criminals do. Did the gangsters and mobsters suddenly become model citizens when Prohibition ended? No; they moved on to other criminal enterprises.
Saying that all criminals and criminal enterprises are the same and do the same harm to society, which is what you appear to be arguing, is laughable on its face.