The answer is because Hannity is talking about how he's "Breaking these stories" and doesn't want his general audience to know the sources of his schtick & how he's otherwise pretty lame when it comes to figuring things out.
I agree with your remark. Hannity almost never gives credit to anyone else. Says he spends all his time before the show reading, but then doesn't credit where he got the info. from. I've always thought he or his staff lurk on FR.
Hannity has a place, but I don't listen to him much anymore.
For the most part, he's a Rush parrot. IMO. But most of his audience is/are "A Great American." (tiresome)
That about sums it up. There are at least three other folks that I'd like to replace Hannity, since half the time no one knows what the hell he is talking about when he uses sixty-three pronouns, discussing eighteen different topics within 32 seconds.