Someone asked this on an online forum, and I think it’s a reasonably question.
Honestly, when I hear this, usually from HR when we are trying to do a placement, it sounds bizarre. Companies I work with that are actually high-functioning are much more worried if the people are willing to work in an open space environment, if they are collaborative (as opposed to territorial/”you do your job and I’ll do mine”) and if they are willing and open to pairing. The rest of the stuff is easy.
The people who insist on Agile Experience are typically in the early throes of adoption, or worse, in some sort of long-term compromised adoption where people are arguing about how Scrum “right” means this or that, what words mean, etc.
Jerry Weinberg’s book, “Becoming A Change Artist” might come in handy about now. (Don’t worry; he won’t ask you to meditate and listen for your inner voice; it’s volume 7 in his quality management series.)
Specifically, Weinberg introduced me to McLyman’s Zone Theory, which suggests that any change goes through multiple steps. In “The Red Zone”, the foreign element (“Agile”) is introduced, and actually disrupts performance. Things struggle until the team “gets it”, and the transforming idea kicks off — the yellow zone. In the yellow zone, the team is going through skill development, and another disruptor could make the team slip back. Once you hit green, the concept is established.
Teams that insist candidates “know” Agile are worried about failure, about sliding backwards, about stupid arguments. They are in the red, or possibly, yellow zones.
To put that more simply: When I hear “must know Agile”, I see a team in conflict, or, at least, a team that had some conflict recently and is worried that an outside who “doesn’t get it” will cause performance problems. It’s not that I can’t work with such a team — they likely could use some consulting! Instead, it’s a yellow flag for me to ask more questions and to be cautious, to understand the lay of the land before I commit.