As I grow with Agile, I have to agree with three things in this article:

1. People have varying definition of what Agile really is.
2. Some people have too much confidence in their own perception of Agile.
3. Some people have too little confidence in Agile due to their own misconception about Agile.

What I do to tackle that is to find a common reference to Agile and that is Agile as defined by the Manifesto and Principles created in 2001. With that, variations can be minimized and discussions can proceed using the same language. From there we can move to Scrum, Kanban, Extreme Programming, or any ad-hoc Agile method that is suitable.