I'm not going to say college is the only way, but a lot of successful non-college-educated entrepreneurs go way too far in discounting it.
Now, I get it, it's getting incredibly expensive, too expensive actually in the US, and you'll learn a lot of crap you don't care about. The funny thing is, as my career has advanced I've used more and more of the stuff I didn't want to learn. Hell, this would probably be a much more convincing comment if I'd paid attention to my written argument class! (Hilariously I argued against liberal arts requirements for technical majors in that class...)
Aside from the subjects one learns and the new ideas one can be exposed to there's the networking aspect. Who you know is hugely important, it can help define the opportunities one has. I have my current job literally because someone knew someone, who also went to the college I went to so they thought I was a good candidate.
Another perfect example is Mark Zuckerberg, who literally built Facebook because of, and with the help of, his college network.
If I'd realized the importance of a well-rounded education and of networking when I was in college I'm sure I'd be much further along in life right now. Probably retired on a nice tropical island actually...
Anyway, point being that you don't necessarily need college but it can definitely be useful.
He didn't finish college. The value was the people he met. Which I discussed heavily.
As I discussed the value of the people he met... and yes as you said you meet people working in the trades as well, but does that mean everyone should work in the trades?
While he didn't finish college he did make it through two years and undoubtedly used the knowledge he acquired.
The reality is that people can succeed without college, but statistically chances are improved for college graduates: http://theconversation.com/the-myth-of-the-college-dropout-75760