Dogma v's Reality: Reality always wins
It never ceases to amaze me how people get caught up in the dogma of methodologies; how you must do X as that is what is in the book. This is particularly amusing when you hear people saying you must do X to be Agile. I cannot but think they have missed the point; being Agile requires you to be flexible in your dogma not dogmatic in your flexibility.
The team I have worked in that best exemplified the values of the Agile Manifesto was twenty years ago. We were developing mainframe applications using Cobol and SSADM yet embraced and displayed the values laid out in the Agile manifesto: open communication; putting the customers business needs first; regular releases of working code; not doing unnecessary work; and regular process improvement reviews.
The lesson I learned was that it is not methodology X or technology Y that makes you an Agile team, it's having the mindset to be willing to be Agile. Of course this requires people who have the wisdom to be able to take toolsets and choose which tools to use; which ones to leave in the box; and when you need to make a new tool for a particular job. If you have wise people they can adapt any methodology to work well in the reality of a situation; those who lack wisdom will try to apply it dogmatically and insist that reality change to suite the dogma. The former tend to have successful projects and the latter failures; because reality is always trump.