Why are people still pursuing degrees which they will likely NEVER be able to use? This is not a problem that universities need to fix, but it is ultimately a self-correcting problem. If people can't get paid for studying X for 7+ years then post-grad X programs will dry up and disappear. As they should. If you're planning to go into one of these dead-end academic fields you should be required to take a full year course in Economics first.
Looking at the Excel chart, it seems like most people in debt got that from undergrad, not grad school. The data doesn't seem to support their conclusion (that people rack up debt in grad school).