Focusing on the "yes, I agree" areas helps you to connect with them and get on the same side. From there, they will be much more willing to reciprocate by listening to your side of things.
Maybe it wouldn't work for the author, but I've found success with it.
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To be clear, this is not about some new age pacifism. Sometimes looking for someone to blame is a knee jerk reaction, sometimes placing blame is a calculated manoeuvre. In both cases, often, it is not good strategy to face the "attack" head on.
This is the whole self awareness thesis -- now you know that this is how you respond, and this is a strategy to deal with it.
Don't get hung up on introvert and extrovert traits. They're not relevant to the message.