> Unlike the people I met in the Silicon Valley, only a handful of our tech-oriented students had participated in hackatons, contributed to open-source software, had started a personal blog or answered questions in online help communities such as StackOverflow.

The overwhelming majority --by a huge margin-- of entrepreneurs have never done any of this.

Your perception is skewed by reading HN and following the Silicon Valley "culture". That isn't at all a reflection of the majority. In Silicon Valley and in politics there are certain things you might have to do to signal club membership.

In the case of starting and running a business none of the items you list are a necessary part of success at all. I know people who are doing multiple millions of dollars a year in revenue who have never gone to hackathons, contributed to OSS, started a blog (that one is particularly funny) or spent time answering questions on SO.

The shadows you are looking at are not reality.

Note: Before anyone thinks that's an insult, google "Plato cave" and read it.