And yet GDP per person has trended upwards in a pretty global fashion. [0, 1] So either those providing "real" value are so productive that they support all that dead weight and yet still continue to grow, or those "bullshit" jobs are actually providing real value and increases in productivity.
[0] http://www.bls.gov/ilc/intl_gdp_capita_gdp_hour.htm#chart03
[1] http://www.bls.gov/ilc/intl_gdp_capita_gdp_hour.htm#table01