Err, uh, where do you get the idea that Khan academy "has ushered more people into STEM than any single person"? Seriously. I don't even know how you would measure something that.
Ok, so it's a very bold claim from my side - but he's done a phenomenal job making fundamental math (and science) lectures accessible, and more so, he does have a teaching style which works for a lot of people. It has been much faster paced, and more concentrated.
As for pure numbers, his videos have a total 1,806,946,640 views and 6M subscribes.
(Sure, there are scientists and inventors that have inspired magnitudes more people to enter STEM over the years)
