Withholding Information For The Book

The problem with journalists knowing things but not sharing them is that it taints all of their reporting. If I know something but can't share it, I have to dance around that fact. If someone claims something that contradicts what I know, but can't share, I can't then point out the contradiction.

A defense for these things is that sources will give the information with the agreement that it won't be shared for a year, but not otherwise. And, ok, sure, but it also means that the journalist spends a year doing stories on the same subject having to, at best, carefully maneuver around the contradictions.  

It isn't just failing to report it in real time. It corrupts the reporting of everything. Maybe the contemporaneous stories they write are done responsibly, but all of these people go on cable news and chat and they can't avoid participating in a dishonest conversation, even if they are personally not being dishonest.