When I wrote the first version of this article six years ago, I called it "Why Free Software usability tends to suck". The best open source applications and operating systems are more usable now than they were then. But this is largely from slow incremental improvements, and low-level competition between projects and distributors. Major problems with the design process itself remain largely unfixed.
Healthcare professionals have observed an increase in levels of childhood obesity. This increase has been attributed in large part to physical inactivity. Physical inactivity can lead to obesity and poor cardiovascular health, and it can also have negative effects on bone health.