The article's main criticism is that KA doesn't try to talk about all the possible uses of the subject matter. I'd rather they didn't, or at the very least kept it separate. Unless someone's being forced to sit down and watch educational videos, that doesn't add enough value to justify the time spent.
It may be that other competitors (including the ones you've mentioned) will try to fill the gap and take a more traditional education role. But saying something's bad just because it's not occupying the exact niche that the author wants it to? That's not a very useful criticism.
I'm no teacher but if I was I'd much rather spend my time getting kids excited about stuff and then point them to the resources they need to get going. I'd also have more time to answer questions so the kids wouldn't get as frustrated or stuck.