We are told that if we succeed in life, it is because we are smart, strong, winners. If we fare poorly, then it is only because we are stupid, lazy, losers . Never mind economic reality or personal potential, we are told that if we will it, we will find a way.
Soldiers are in effect workers in uniform.
They live and work in proletarian conditions. They learn skills which they will then apply as workers once they leave the service. They learn military skills which will be of great use in a revolutionary situation. The army is made up of a disproportionate number of Latinos and Blacks, and poor people in general. These people often can't find jobs in the real world, so they join the military in order to get out of poverty, learn a career, get money for college, travel the world, etc.