Happy to tell you more. My name is Karim. I'm the founder of Mathalicious and the author of the blog post. I'm also a former classroom teacher and middle school math coach, where I worked with other teachers to help improve instruction by focusing on 1) conceptual understanding, and 2) relevance.
It seems like the anti-post comments fall in three categories:
1. Khan is great
2. Mathalicious is just jealous
3. The author of the post is part of the establishment and should be ignored
Let's take those one at a time.
First, Khan is great for what it is. It's a wonderful resource for homework help, for review, for a refresher, etc., and I said as much in the post. However, Khan Academy is not great pedagogically. It presents math as a series of steps, is entirely traditional, does not address conceptual understanding, and should not be the first touch-point for students learning math. Unfortunately, this is exactly what's happening in any number of schools across the country, and the worry --- and it's not just mine, but many in the education community --- is that it will merely perpetuate the problem.
Second, the "you're just jealous because Khan is eating your lunch" critique is a bit silly. Mathalicious provides lessons to classroom teachers, not direct instruction to students. If Khan Academy were effective at teaching students in a meaningful way on the front end, this would actually be good for us. Our lessons focus mostly on applications of mathematics, and in this sense are the yin to the yang. Regardless, the critique that Khan's style of instruction is ineffective and has been proven so has nothing to do with something so subjective as jealousy. It's objective fact, something I'd imagine would resonate with computer scientists. That said, would I like it if Mathalicious had Khan's millions? Absolutely. Not only would it allow me to have an income --- something I've foregone for over two years --- but it would more importantly allow Mathalicious to make its lessons free to teachers, something that we simply cannot afford to do. (Still, we do allow users to choose their own price, including $5/month: the price of a Starbucks coffee.)
Third, this issue of my being part of the "establishment" because I'm a teacher... As a teacher, I've seen first-hand how broken the system is. I've taught next to people who knew very little math, and that frustrates nobody more than the teachers who have to pick up their slack. Either way, the "change must come from outside of the system" argument suggests that teachers therefore have no role to play in education reform. If there's anyone who actually believes this, please raise your hand.
In the end, here's my argument in a nutshell:
1. We have a math crisis caused by ineffective teaching and an emphasis on rote skills
2. This style of teaching has been demonstrated by research not to work
3. Khan's style of teaching is the same
4. Cash-strapped schools & districts are beginning to adopt Khan Academy as a core tool
5. This won't work and risks perpetuating the problem
6. We know from observing other countries that, to solve the problem, we must invest in professional development and effective curriculum
7. In part because Khan is free, and in part because of a sycophantic media narrative, we are less likely to do this so long as we think Khan Academy is the solution to the problem
So, what part of that do people disagree with?
Karim