I'm going to quote you on this :-D You're exactly right. I did a philosophy class once on the many ways Descartes was wrong. Very confronting stuff. I do love the term design thinking, but not in the context of "bare with me, I may design, but really, I also think".
What I like is: "I can design my future, maybe not by making artful sketches and colourful collages, but by thinking creatively, iteratively and in a 'what if' sort of way". That way it takes design out of the realm of skills (only available to people with complex glasses and black polo neck jumpers) and into the realm of the guy next door. I hope this is what most people mean when they use the term 'design thinking'
Unfortunately, designers have no monopoly on "if you only listened to me, everything would be just fine. Printers, teachers, policy wonks, ivy league grads, etc.etc. My own theory is that it's all Descartes fault." I think therefore I am. "That's exactly wrong. Any one knows that it's "I am therefore I sometimes I think."
I have to say that my problem with "design thinking" is that it brings to mind. " I think , therefore I design." instead of the other way round.
I must say that I find the notion that designers have the kind of power to 'design" a culture a holdover from designer as hero. If only they would learn to practice humility the insights they've earned could be so much more useful. I didn't want to clog the thread on the upcoming conference, but my 2cents is it should be something like "Making service design suck less for a better world.