It’s funny, I was talking about this exact topic over brunch this weekend with my friend who is a PhD student at NYU. She was saying that TED Talks have set this expectation for teachers to be entertainers as well as educators. It’s not enough to merely have a mastery of your topic; now you’re expected to put on a performance when you teach.
Rather than the student and the teacher making a joint effort to engage with (often difficult) content — the student by making an effort to learn and the teacher by presenting the material well — now the burden has shifted entirely towards the teacher. If the teacher isn’t as riveting as a TED Talk, then the student can’t be faulted for not paying attention.