Read it if you haven't yet.
Here are the pearls that made me post this:
“If you don’t have meaningful feedback then you’re not agile. You’re just in a new form of chaos.”
“Agile practices build a technical and organizational infrastructure to facilitate getting and acting on feedback. If you aren’t going to adapt to feedback, then this infrastructure is waste that will only slow you down.”
This is very much in line (or even the same) with one of the tenants of the TPS (Toyota/Thinking Production System), the PDCA cycle. In order to improve you need to learn, feedback is the fuel for the process of learning. No feedback no learning.
If you are not learning, you are not Agile. No matter what you are doing!