There's a spectrum isn't there, between weasel words that are avoidant and non-attribution which is done out of respect or kindness. News is full of passive prose; "A source claimed yesterday", because anonymous sources need protection. A barrister might say in court; "It has been said that...", not to invite libel or misidentify a witness. Or a teacher might say "It's been brought to our attention that some children..." not to embarrass a kid in front of everyone.