Agile Doctor

I quote this principle verbatim to all the teams I coach constantly because it is the only completely prescriptive principle. While other principles use more vague words like "early", "late" or "shorter", "daily" is not open to negotiation or interpretation. The word "must" is also unequivocal as are the roles described. That prompts the following question - why were the founders of Agile so strident with this principle while allowing for broader interpretation with all other values and principles?