I think is is like most other aspects of work and trade nowadays - not so much lack of skill, but rather the lack of a decent work ethic.
My observation is that there have always been craftsmen and hacks in every area of the working world. The craftsman takes interest in his job and its relationship within his specific industry. He takes pride in his work and will produce a superior product pretty much regardless of reward or other benefit to himself. His main motivation is internal. The hack, on the other hand, will do the minimum he can without getting fired. He takes little to no interest in improving his skill, nor does he give any thought to how his job interrelates with that of his associates or coworkers. He generally believes he is underpaid and uses that opinion to justify his lack of quality. His motivation is external.
As I mentioned, there have always been these two classes of worker. As far back as I can remember personally the true craftsmen have always been rarer than the hacks. The trend has been a decline during my lifetime, and now the hacks vastly outnumber the craftsmen.
My father was the epitome of a craftsman, and although I chafed at it at the time I am so glad he instilled those values in me. My working life has been much more fulfilling because of it.