I may be old and set in my ways, but I am glad they don't work on mobile. I want you to be focused when you are taking a class, not trying to fill the minutes in line, or do so while sitting in the cube at a call center.
Also, the final paragraph in the article makes a good counterpoint to this:
> Michael S. Roth, the president of Wesleyan University, is teaching a course in European intellectual history on Coursera. "People have to get over the idea of signing up for a course and not finishing it," he said. "We all have to get over feeling guilty. There is no right way or wrong way to use an online class. This is a great platform for lifelong learning."