Living in a dorm room is different from living in an apartment. Eating at the dorm cafeteria is different from cooking for yourself in an apartment. Being part of a fraternity or the marching band (or a football team, in Bubba's case) is different. Playing intramural sports in a college league is different than say, playing them in a church league or just with your friends. In college, the professional world and the personal world is blended into one, where you often go to class with your friends, who are your own age, and you're basically with people your own age constantly. In the professional world, you work with whoever you work, whether they're your age or not, and there's less potential to meet new people (since you're not surrounded by 15,000 other students). There's no reason a ditch-digger couldn't go to lectures and read books about philosophy, but generally there's more potential for somebody in college to be exposed to new ways of thinking and to meet people of different backgrounds.
I, for example, roomed with a Pakistani Muslim student my freshman year. That was an experience I never would have had if not for college, and it is an experience that changed the way I viewed the world. Sure, somebody else could have had that experience without school, but I probably couldn't have. Some other people probably didn't have that kind of experience in college, and maybe would be more likely to have an experience like that in the professional world. There are also experiences I will never have, since I'm not in the military, or since I'm never going to be a rich CEO. There are things I will miss out on from not experiencing those lifestyles, just like anybody who doesn't go to college is missing out on some of the unique aspects of that lifestyle. The college experience is more than just "growing up," just like getting a job or joining the military or whatever is more than just "growing up."
The point is, whatever Bubba decides, he's at least somewhat closing the door on some opportunities. His life, should he choose college, will be different from his life should he choose professional baseball in more ways than just his financial comfort.