There's some meta here worth pondering. "Deisgn Thinking(TM)" and its ilk are inevitable, in a culture built around 'products'. There has to be a simple, clear, marketable to a dumbed down population product of some kind to sell. But design as a fundamental human practice can't be packaged and sold.
Most people in our so-called 'modern' world have had their innate ability to observe, comprehend, and engage with systemic complexity beaten out of them since birth. Our professionalization of everything that used to be communally held and practiced adds to this pathology.
I imagine what Tim Brown might have meant is "everyone would (still) be a designer, if we hadn't thrown design as everyday human activity out the window long long ago in our mechanistic-deterministic cultures."