I wanted this to be better.
Average high school teacher salaries in the United States
Average and median professor salaries in the United States
That Ph.D with a shitty chance at tenure? He's pulling down a minimum of $45k per year. There's one state in the nation where he can hope to do that well starting out. If he gets tenure? He's got six figures. If he kicks ass at teaching high school? Maybe half that.
I put a social worker through grad school. Most social workers end up in HR. Not because they don't want to heal the psychic wounds of a desperate nation but because they want to pay off their student loans.