I agree with @xxii about the college experience being more important than the actual degree.
College takes place at a very important time during the brain’s development, and what better place to be during that time than in a college setting? Even if you spend much of your college life partying (as many do), you’re still likely to get some education and experience that will help you become a mature person. I know a few people who went into the military right after graduating high school and went to college after, when they’re in their late 20’s or early 30’s… most of them still act like immature high school kids (especially the guys). Those people, I imagine, will have difficulty in life just in a social manner, since they never had the chance to grow up.
Going right into show business or the music industry is usually not a great idea straight out of high school (or even before that, as some seem to do!) as it doesn’t have any sort of “retirement” plan. You get a certain amount of money per movie/show you do, or how many albums you sell, but what happens when no one likes you anymore? Most celebrities don’t seem to do much in the way of saving their millions of dollars, so they don’t have much to go on financially or educationally afterward. I don’t know much about sports, but I would imagine it’s a similar situation. Many former athletes become coaches, but that can’t be the case for everyone who takes the field.
It’s sad that your brother’s classmate didn’t end up pursuing his passion, but really you have no idea what it would have been like if he had gone into baseball. It could have gone very well or it could have ended horribly. Most likely he wouldn’t have become the next Babe Ruth and he’d be stuck trying to assimilate to a world where you are hired based on how much skill or education you have, not how well you can hit a ball.
That being said, many of the famous actors, musicians and athletes out there decided to forgo the traditional course of education and follow their passion, and they obviously had great success. It takes passion, dedication, perseverance and luck to succeed in these fields, which don’t always equate to a college education.
When my sister, in elementary school, said she wanted to go to beauty school and become a hairdresser, my parents said that would be fine – after she finished college. She got a psychology degree with a minor in French and is now making a good salary selling expensive bras and underwear. She may never go into a field that uses her degree, but at least she’ll have that to her advantage if she wants to go into a different career.