For example, if I were to be chronically unemployed and quit looking for jobs altogether, I would actually help the unemployment rate look better since I'm no longer part of that metric.
Part of the problem can be attributed to automation in jobs and job duties, thus requiring a smaller labor force. For those who were laid off by automation in manufacturing or other sectors, many would likely have a hard time finding a job in their established career. Expecting most of such workers to get a job an an on demand skill like maintaining machinery or software development is a herculean task. Most likely they are the ones who fall prey to the poor labor participation metric.
[1] https://www.investopedia.com/ask/answers/061515/what-key-dif... [2] http://www.startribune.com/even-with-unemployment-at-50-year...