The advice he gives about keeping your word is good advice. I try to keep my word, and I enjoy working with others who do. However, committing to do unreasonable things in an unreasonable time and then not being able to finish them is not so much about "keeping your word" as it is about being realistic. No matter how great you and your team are, you have to set realistic goals and doing that is not being "normal" or "average" it's being reasonable and having a work/life balance.