Actually, yes. Nixon was a son-of-a-bitch, but that doesn't mean B & W didn't violate the public trust. For several months in the 1970's, a virtually unknown spook paralyzed the government of the most powerful nation on earth. And Woodward & Bernstein covered it up.
Refusing to name sources is about two things: actually protecting people in danger, and protecting your rep as a journalist. Felt's safety was never an issue. This is a man capable of bringing down the president, right? He was sitting on 50 years of dirty secrets collected by JE Hoover. No one dared touch him.
So B, W, and their editor kept quiet for purely selfish reasons. Then they willingly let themselves and their paper be used to settle a personal score against Nixon. They provided Felt with cover to make his leaks more effective. All the while they painted it as a home run for integrity and democracy, when in fact it was a political feud.
How is all of that not that a violation of the public trust, ie, corruption?