Dolphina:
G-d commands us to rebuke wayward Jews and return them to the path of righteousness. Your idea that no one should judge others because they themselves have also sinned is an idea which comes from Yoshke and is not a part of Judaism. While it is true that one should not cast aspersion on Jews, it is also true that as a nation we are all responsible for one another and when there are problems which are endemic to a significant portion of Klal Yisroel, we have a responsibility to help them navigate to the right path regardless of if they want to or not.