While autodidactism is certainly laudable, there is value in a corporate educational setting, namely the value of intellectual interaction. College is not so much about learning a set of data, but learning how to learn. (For the ultimate example, consider the Ph.D., a degree meant only to teach you to do research, and requiring legitimate research to attain it.)
Now, I'll admit, I was educated in a liberal arts[1] high school, and am currently pursuing a couple of liberal arts degrees. That is both why and because I believe education is about thinking, not committing facts to memory. I eschew academic engineering because it is (at my university, at least) primarily a series of courses that certify your knowledge of yet another parcel of facts. That is useless, educationally. As technical training,[2] great, but it's not education.
Your list of "why"s implies that, substantively, you were no different at the end of college than at the beginning, modulo a group of friends, and four years aging. If that is the case, I'm terribly sorry; you managed to miss most of your education.
[0] Mea culpa: this entire comment is a bit hot-headed. You've hit a pet peeve. [1] Before you jump to conclusions: the liberal arts include the hard sciences. [2] In all honesty, that's what engineering school is: a vocational education in an incredibly advanced vocation. (That's not a problem, really: I share my time between my liberal arts degrees and a fine arts program, which is also vocational education, in a (imho) advanced vocation.)