Job Bowl

So the Super Bowl features two teams whose mascots are named after large groups of out-of-job laborers, namely, butcher-meat packers and steel-factory workers. Why doesn't the N.F.L. just go ahead and change the names of other teams---thus the New England Empty-Net Fishermen, the Detroit Laid-Off Automakers, the New Orleans Katrina Survivors, the Seattle Former Aerospace Engineers, etc.?