A person who is too busy, too stressed or too knowing — or all at once — cannot hear anything outside their immediate understanding. In other words, they cannot philosophize, and will not permit philosophy to happen in their presence. Their world is a world of expertise.
I define philosophy as Wittgenstein did: “the structure of a philosophical problem is ‘here I do not know how to move around.'” Philosophy is attempting to think the unthinkable. Expertise is the efficient application of established thought.