I know one who does it because he is an alcoholic and a pedophile. Point being, having a Ph.D. doesn't mean you can't screw up your life in a variety of ways that limit your career options.
The point of the article is many of these folks actually want to be janitors. They have no debt and want a job that pays for 8 hours, but requires only 2 or 3 of actual work.
Indeed. These sensors are the impressive part of wearables, it will be tough to build a differentiated product on top. Invensense becomes the Apple/Samsung, and the wearable maker becomes an app, but with hardware development timelines and costs. The way to win is if someone can make a "killer app", and continue to innovate faster than competitors simply copying what works.
Not being being able to do the symbol manipulation is a different problem. That's what you see from the students who have B's and C's in their previous math courses. The problem discussed in the blog post is what you see from the A students. It's probably more obvious in a class like analysis than in calculus.
