As I've said many times, a degree is just your ticket to being some else's bitch.
It's also worth bearing in mind that spending 3-4 years focused on learning stuff like math,econ and CS rigorously can help your abilities to build a business later.
You might be able to setup your web dev shop at 18 and make a nice living for a few years making CRUD apps or whatever but once the market starts to demand something else then you are likely to get stuck if you haven't put some study into higher level principles.
Besides there is nothing stopping you from running a simple business at the same time as going to college. Myself and a few others on my CS course used to build websites and fix PCs during the holidays and made more money for about half the hours as the people working at the supermarkets and pubs.
A common mistake people make is that any given subject (math, econ, etc) is limited to your studies in college. I have studied biology, architecture, the classics, geology, meteorology, botany, and much more outside of college.
It does depend whether or not you are a self learner, but is paying 120k+ really worth it to have someone twist your arm? Everything you can learn in college, you can learn outside, for free -- the interent has democratized information.
That aside, you can learn anything you want outside of college, for free. Information is free, thanks to the internet.
A person may decide that it's not worth investing 4 years and lots of money for the sake of a degree, but a degree has advantages that should not be ignored.
I'm mostly speaking from personal (and vicarious) experience - when I graduated from college, I put out around 100 job applications -- no response. Then I released my first project, and had employers coming to me (Electronic Arts and Pixar, to name two). Make your own destiny -- all a degree gives you is an unwarranted sense of entitlement.