Hey, it's all relative. This is not far from saying, "only 50% of jobs are above average!!!"
First of all, that's only true if the average (i.e., mean) job is the same as the median job. Then your 50% claim would be true.
Okay, /pedantry.
Now, the issue addressed is not whether one has an average job. It's whether one has a quality job. In a perfect world, 100% of all workers would have a quality job -- one that allows them to not just survive, but thrive, prosper, and be happy. Of course, we don't live in a perfect world, and probably never will, but at least let us strive towards that end.