My twin sister and I were homeschooled up until ninth grade when the difficulty of math outstripped my mom's ability to teach it to us. So we ordered a stack of VHS tapes featuring Leonard Firebaugh and his whiteboard. I can't believe I've never connected his videos to Khan Academy until now.
Those videos were boring but I was grateful for them because the alternative was nothing. So let me say that I completely understand the enthusiasm you'll find from homeschool parents in the comment threads of any given report on Khan Academy. (The religious homeschoolers offer Khan their prayers in addition to their thanks, and I understand that too.) When Mark Halberstadt thanks Khan for helping him clear hurdles to study electrical engineering at Temple, I don't have anything in me except gratitude for the fact that something existed for Halberstadt where once there was very little.
I was grateful for Leonard Firebaugh because the alternative was nothing. But better than nothing and better than Leonard Firebaugh were the classrooms of Messrs. Selim, Cavendar, Bishop, and Whipkey, where we did math more than any one person talked about it, where I had to unlearn and relearn a lot of Algebra I thought I had mastered. You couldn't combine the two. You couldn't pause the doing of mathematics and then turn us over to watching someone else do mathematics for upwards of ten to twenty minutes. It would have been a collision of two hostile worlds.