Judging by Barr's past actions, it's this anon's opinion that Barr is legitimately aggravated at POTUS.
Any truly non-partisan individual would be, in his position; It just makes his own job harder.
>how do trumps tweets fuck with his job?
The Court of Public Opinion includes everyone involved in any investigation that does not have the whole picture. Therefore, any decisions made due to perceiving partisanship will effect investigations negatively, which Barr does not want.
He's got a record to uphold. He got where he is, due to that record.