> Unless you get inside the activity and identify with it, you are not going to be good at it.
..taking the statement you quoted out of context ?
I don't quite agree it is a terrible generalization. I do not think you can become good at something without actually identifying as a 'do-er' of the said thing; without actually getting so involved with the thing that it becomes part of your identity.
Also, on the thing you say about educators -- who else, if not educators, would you listen to if the person telling you that math education needs to be impress upon students, mathematical thinking (as opposed to than bland mathematical procedures )? Wouldn't they have the most context ?
PS: also, unless you are a mathematician and/or an educator, I hope you do see the irony of your comments dismissing as 'exceeds his field of expertise', the opinions of someone who is both.