Agile Manifesto Background
The circumstances leading to the Agile Manifesto are quite different than what most people realize.
During the 1980's and early 1990's it was common for companies to hire a software consultant (contractor) to help develop a custom software application for the company.
It was the age of application generators. There weren’t many ready-made good software packages to buy, and if so then they needed additional custom development.
When you build custom software, a feature set, budget and timeline are all locked into a contract. Then if you add a feature, you need to ask for more money, more time, and amend the contract. Doing so over and over does not go well with the customer.
So the Agile Manifesto is a proclamation document listing preferred values and principles related to custom software development.
The objective was to provide a better way of building custom software for customers in a manner that would be productive and would reduce undue negotiations with the customer.
The Agile Manifesto was never meant for commercial software development.
It all becomes very clear if you read the Agile Manifesto in the context of custom software development.
For detailed information, see the Origins of the Product Manager vs Product Owner Dilemma article.