Yes, they do make education accessible. Consider courses on AI for Robotics, Probabilistic Graphical Models. Learning these topics directly with the books and without the forum support is at least 3-4x tougher in my opinion. And for people who believe that everything is available on the internet - you are wrong! There is material from grad courses in AI that is very difficult to approach directly from the papers or the books. An example is the Reinforcement Learning Course on Udacity.