For damned good reasons.
Not long ago I'd have said "Until the EffingBI and DoJ clean house and start firing and prosecuting personnel who lie and break laws and violate the public trust, this is only going to get worse." Problem is, the idiots in charge- and a bunch of their minions- basically considered such statements and said "Hold my daiquiri and watch this!"
So now we have another case of feds lying in sworn statements, hiding/screwing with evidence, and otherwise doing things that they put plain old citizens in jail for, and whining about being caught. And demanding respect when they've thrown away any reason they should be trusted. Yeah, I don't doubt there are honest FBI agents who don't abuse their authority, or break the law; there are DoJ lawyers who don't do those things either. Guess what?
It doesn't bloody matter. Because all the ones who DO do those things get away with it. Over and over. And completely screw- no, they take integrity and honor, wipe their ass with them, and flush them. And, knowing that, why should anyone trust ANY of them? Basic statement: "You may be one of the honest ones who don't do that crap. But since I don't know you, and don't know if that's true, then I'd be a fool to trust a word you say."
Comey and his fellow shitheads, and the corrupt bastards at DoJ, have trashed trust. And I really don't know if it'll be possible to rebuild it. Which is a really depressing thought.