Hackers, this is a case study in anti-patterns for a demo site.

Huge complicated UI, takes multiple clicks and ends at a dead end. Not even an pictures of example output!

I expected this to be free in the same way that Khan Academy is free. I don't see how this ties in with their payed service (wolfram pro isn't really aimed at kids).

Pay wall - for a problem generator?

You can't even generate any problems unless you're a Pro member.