I was explaining exactly this phenomenon to a friend, couple of days back. I see this trend inherently tied in with the increasing availability of self-learning resources by virtue of internet and initiatives like OCW, p2pu and others. This makes it possible to break out of the academic mold in which the undergrad/grad degrees put you. This also makes it possible/easier to keep the skills up to date in your chosen field.

I don't know how industrial revolution felt like to those who lived through it, but I am seeing more and more people around me jumping the ship everyday.