I have known quite a few of them and most of them are really good guys who are honorable and serious about their jobs. I have also known a few who enjoyed their drink and had a wandering eye.
You can say the same thing throughout law enforcement, the courts, churches, boy scouts, the Amish, social services, banks, the CIA, the military, and any other organization that is composed of men and women.
I suspect the issue here is that one or a few compromised themselves (pretty serious given their mission) and the others did not do anything about it (also compromising the mission) but that is just speculation and I will wait to hear more.
There are honorable people in the Secret Service.