That's a common misconception. The days of taking anyone who walked into the recruiting office are long over. US Navy recruits are, on average, regular middle class youths with a high school diploma or some college. Most of them could do fine in the civilian labor market if they wanted to.

The truly desperate people don't even meet recruiting standards due to criminal records, health conditions, drug use, low fitness, bad test scores, lack of a high school diploma, etc.