The biggest issue is that by insinuating that Brady had taken PED's, Belichick diminishes his legacy even further, Spygate, sub 50% record without Brady and even his achievements could only have been made by having a steroid abuser as his QB. I don't think whoever is supplying that info to Wickersham is very bright, whether it's Bill or someone else close to him.
This isn't tennis, where a coach tries to wash his hands of his pupil by creating rumors for being insulted after getting fired. If Brady took PED's, everyone's success and achievement with the Pats gets a dark cloud over it. 6 rings? No one would respect them again. The same goes with creating accusations. It's not only Brady's success that gets thrashed and tainted, it's Bill's, it's Kraft's, it's McDaniels', it's everyone.
How can people who have worked for the Pats, or are still working for them, be this dumb to throw under the bus the entire organization by thinking they are simply slandering Brady?