He's a reporter, his job isn't to play "gotcha" but try to gather information, and alienating the PTB isn't the most effective way to do so.
A lot of "reporters" are click bait artists, driven by the need to generate traffic to sell advertising, so they want to be controversial.
Charlie has to balance objectivity with access, antagonizing FO personnel for no reason other than to get his (or the fans') jollies would be counter-productive.
The Athletic is now owned by the NYT, so I'm sure they're fairly stringent about journalistic ethics.