I agree that it is unfair and perhaps even unnecessary to focus solely on Khan here. But I think it must be acknowledged he has caused (intentionally or not) a ton of damage to the state of education. He sparked a movement of “innovation” and “disruption” that managed to push a lot of unproven teaching methods that ran against standard pedagogy which made a lot of entrepreneurs a lot of money.

I don‘t think Khan is solely to blame for this. These entrepreneurs would probably have done equal amount of damage without Khan, siphoning funds away from proven solutions like paying teachers and providing school lunches, and into ballooning administration costs and 3rd-party tech companies. However Khan is for better or for worse the face of this movement and will justly or unjustly get that blame.

Duolingo is however less ambiguous. There is very little language learning going on on their platform. You trick people into playing their stupid game and watching their stupid ads, thinking that they are learning, when in fact they are not.