As someone who works at a university I would agree with the comments above that say uni is still part of the 'real world'. Its a different type of education from school and college too, where the students are encouraged to think for themselves and look after themselves. For me, university was about growing up, finding my feet, figuring out what I wanted to do as a career, getting an education, making friends, doing sports etc etc. I.e. it is not just about getting a degree at all.
However, uni only really works well for someone if they put the effort in. If they do that, they not only get a good degree to stand out from the crowd a bit, but they also build their transferable skills (e.g. communication, computer literacy, numeracy, english skills etc.) so that they can then go into a career that suits them. You might do a degree in a particular subject - that doesnt mean you'd be stuck in that subject forever more.
I would not necessarily say that the uni environment is closeted, it is more of a 'community' and every student has different interactions within that community. Furthermore, subjects can be highly practical (e.g. engineering) or highly artistic and there really is something for everyone.
Encourage your son to visit a university open day or two to see what its like. Be pro-active about this now - dont wait for a school to organise a visit. I did - and I took my parents. My parents were as interested as I was since they never went to uni themselves. Perhaps such a visit would open your own eyes too. If he is thinking of uni, and if it can be afforded, I would also encourage him to go somewhere that is quite far away from family and school friends - the temptation fo home comforts is too much for some and can be a significant distraction.
In summary, university is great - it teaches you how to live your life in a way that schools and colleges cannot do. And go to open days (did I say that already?).