People do not want to leave Hattiesburg. It is completely foreign to them. They want to marry young, have children, and stay within a few blocks of their family.
Move to California? You're going to fall into the ocean. Move to New York? Too much city. Move to Texas? Too hot. Each of those arguments is easily debunked. The humidity makes it hotter in MS.
My life changing moment was taking a Greyhound to Wisconsin with $1,000 and starting my life over. Afterwards, I moved from place to place knowing I could make it where ever I ventured to.
I have female friends in MS who got Masters/Ph.Ds and married the same year they got the piece of paper. Never used it once. It saddens me. Some of those people are brilliant beyond my abilities. Yet, they chose to follow the culture of the community.
People are so miserable there, but it all by choice. My mother had cerebral palsy and received a check for $500/month. We lived in a trailer, and I made it out when I was ~21-23. I had no car, fallback, or family to depend on. I just had to take a risk and go with the flow. It pays off well now.
I have offered people from MS jobs here or connections to jobs here. They would never take that bus.