Part of it (I'm also a dropout, not very successful though, I can pay my bills but thats about it) is the fact that very many social interactions congregate on "what education do you have"? It's a social status thing that people measure other people on in my group of people atleast. Most of the people I socialize with are either doctors, dentists or have a liberal arts degree.
I'm on of the only few with a technical education and I always have a hard time explaning that "yes I did go to college" (I'm from Sweden so it's called University but its not the same as in US), "but I did not graduate".
Their eyes flicker, and I'm instantly degraded to that basement guy with big computer screens they know so well from highschool.
I know very well that my life in very many aspects would be other peoples envy. I organize my days myself, I pay my own salary and I can divulge on whatever project I choose.
However, many people equate a steady paycheck with safety and responsibility. Two keywords that are atleast here in Europe quickly becoming very hot.