The economic reason the job market is once again downshifting is because we as a nation failed to take out recovery insurance in the form of temporary stimulative fiscal policy against precisely the situation we now face.
The president proposed the American Jobs Act back in September of last year for just this reason. The economy in general, but especially the job market, has never reliably achieved "escape velocity," i.e., consistently high enough growth rates that would set off the virtuous growth cycle of more jobs leading to more incomes, more consumption, which feeds back into greater demand, more jobs, etc.