I think my statement was too strong; I definetely don't mean to suggest that nobody who has never followed a curriculum of any sort can ever be successful. What I mean is that in general, as a policy, it is useful to have some curriculum to shed light on the unknown unknowns.

But to respond to "self-study isn't nothing": that's true, but your self study didn't replace college, it replaced self study. What I mean is that everyone has to do that self study and job training targeted at the specific stuff they're doing. Self study is necessary to expand "known knowns" in targeted areas, which is really necessary. It's just not as good at illuminating "unknown unknowns" as a curriculum put together by a person or group of people who know the breadth and history of a field.