Value of higher education:
i) signalling that you are smart, hard-working, or both
ii) networking, connections
iii) acquiring knowledge
iv) having fun on campus, the experience of being at college
I would say the value is probably split 30/30/30/10. Also, to a large extent you get out what you put in.
I know someone who was an army officer, he left to do an MBA and got hired right after by a top accounting firm on a 6 figure salary. He couldn't have done that without the MBA. There are plenty more examples like that.
Sure, entrepreneur types can make a killing. So can basketball players. But what happens if the economy turns down, the business goes sour, you lose your touch etc. Then you are just another uneducated bum with some rapidly dwindling savings. A good education and its status lasts for life.
Example - if two guys are chasing a smoking hot 25 year old woman who wants to get married, and they are equal in most respects but one has a top degree from Harvard or Oxbridge and the other left school at 16, who do you think has the edge? Especially when her parents start giving her advice on who to choose. People are somewhat superficial and status counts for a lot, even though talent and hard work "should" be the only thing that matters.