Post-1970s deindustrialization led to a gradual decline in the availability of work, which eroded the keystone of a shared value system among the people living along the "Rust Belt". I believe it's well-known that the opioid epidemic hit the Rust Belt pretty hard, which contributed to a general sense of bleakness in that time and place. On top of this, 2007 was an unlucky time to be graduating High School, as it was the middle of the 2007-2008 global financial crisis. These forces made up a pretty strong "push", but there was also a strong "pull" at that time: the military was aggressively recruiting in in order to fill the ranks for what's been called the "troop surge", and they were offering generous sign-on bonuses as a result. Joining the military was seen as an honorable profession in a culture and a community that has strong expectations of young men and their labor.
That is a long-winded way of saying that I couldn't find a job that paid a living wage when I graduated from high school, and higher education was seen as a frivolous luxury, and as such it did not even occur to me to pursue a Ph.D. Being in the military sheltered me from the worst of the financial crisis and gave me time to think about what I wanted to do with my life after my enlistment finished. I finally had the luxury of not worrying about my next paycheck, so I was able to reflect on my values when thinking about what I wanted to be. Most of my youth was spent in and around the Adirondack Mountains, and I was raised to have a reverence for the natural world, so I thought that being a steward of the land would be a meaningful and worthwhile career choice.