Possibly, because when you leave school you can realize your misconceptions and learn from other people, as well as pointing out other people's misconceptions. But if everyone uses Khan Academy, everyone will end up with the same misconceptions.
Also, online learning wins in the limiting case where courses have been iterated and feedback / FAQs taken into account. In a brick and mortar institution, "institutional memory" is effectively lost as professors retire or shift interests (if it ever existed in the first place) and their replacements introduce their own slew of idiosyncrasies, poor methodology, and misconceptions. In contrast, an online lecture never suffers this degradation. Sure, new lectures may replace old lectures (presumably at different sites), but both will be available for a time and during that time, students will pick up on inconsistencies. That's not true of brick-and-mortar lectures, where the only source by which a student can verify the material they are presented is the textbook or its alternatives. Combined with the tendency of courses to discourage reading the textbook (it's almost always a less point-efficient use of time to read textbook chapters than to do homework, practice problems, and go to office hours, which provide information better matched to the material that will be tested on), the status quo is a recipe for failure. My experiences confirm that this recipe for failure produces failure (in the pedagogical sense).
The third factor that favors online learning with regard to misconceptions are its twin killer features: the pause button and the rewind button. These reduce self-inflicted misconceptions tenfold.
So, sp322, I think the opposite of what you stated is true. I would welcome a conflicting opinion, because usually when I go on rants similar to the above three paragraphs all I get are nodding heads.
I guess some people are suggesting that Khan Academy is the ultimate in education and that everybody should use only that and nothing else?