The claim didn't ring true to me, based on what I've read about the topic in the past, or based on my personal thoughts and experiences. So I wanted a source. It should be easy to provide a source, if sources are as plentiful as lijok says.

>the standard for communication in effective organizations is to be direct and to the point.

Sounds very nice, but empirically humans often struggle with frank feedback. I think that goes for both subordinates and superiors, for different reasons.

I would argue it can be worthwhile to spend an additional 25% time to make it clear that it's nothing personal, to avoid risking a deterioration of your relationship.

Obviously, it's good to have friendly relations with your coworkers, including your boss.

If you have a high-trust relationship with your boss where there's no risk of deterioration, and you know your boss likes it when you speak your mind -- more power to you. Be direct and to the point.