Like walmart is the largest private employer in the US, the working conditions, pay and benefits one gets from working at walmart isnt comparable to what we used to give what was the largest private employer 50 years ago (which was AT&T) - nor can the margins that walmart generates support those kinds of generous pay and benefits either.
This story is repeated a 100 times over thruout the US - while yes we have full employment, its in service jobs (retail, food service, hospitality) and not in manufacturing or other high paying jobs.
The second thing I'm trying to deal with, for lack of a more polite way (without lapsing too far into euphemism) to put it is "jobs for stupid people" (edit, in hindsight the best way to put this is "good jobs for everyone") - for a significant portion of the population, the best job they can hope for in terms of wages and benefits is working on a production line in a factory, while you and I (presumably) work in some sort of information job - thats just not an option for a significant portion of the population, and until we solve that we're going to keep having an issue with a K-shaped economy.