1) I don't think entrepreneurs (and tech ones at that) have solved any problems, even for the upper classes they cater to. Instead, they have become popular and profitable the old-fashioned way, by creating and filling a need. Even a solution as fundamental as search on the internet is not really helping me lead a better life--though it does make possible the vast stores of knowledge and likely the entire tech sector (including my livelihood).
2) Given 1) above, the entire article essentially seems to encourage people to exploit the under-exploited markets of the unexotic by creating needs there and fulfilling them. I don't really see how entrepreneurs can, for example, fix the bureaucracy of Veteran's Affairs, even if they had a turnkey case-handling solution to sell to them.
Finally, the author of the article had a pedigree as long as my sleeve, but I didn't see any work in the unexotic fields.
Somewhat related thought: where are the non-tech entrepreneurs? Are there solutions that don't require computers anymore? Are there ways to get funding for such a solution?