That's a pretty negative perspective. Not everything has to be about money and getting ahead. I think there's a lot to be said for contributing back to the community for the greater good, without a profit motive. That doesn't mean you have to patch someone else's profitable code for free, but creating your own stuff to give away to the world, or contributing to a project whose philosophy or utility you like regardless of their corporate sponsor, is a very good thing to do.
I'd suggest the opposite of parent comment's advice to young programmers. Don't buy in to the mindset of "how does this benefit me, me, me." If you find yourself in a position where you're happy with your burgeoning career--i.e., having a roof over your head, and not worrying about your next meal--contributing your talent to F/OSS, regardless of who "benefits", is one of the best ways you can apply your specialized domain knowledge to improving the general good. Basically what the article says.
In that case project selection is important. Unpaid work towards a project who's main effect will be to reduce licensing costs for fortune 500 companies is very different to working on something to (say) improve educational outcomes for low income children.
Hacking on open source does increase the education improvement for low income children. Example: Poor kids in Africa now have android phones and have access to open source education materials made possible via open source web technologies.
I'd suggest the opposite of parent comment's advice to young programmers. Don't buy in to the mindset of "how does this benefit me, me, me." If you find yourself in a position where you're happy with your burgeoning career--i.e., having a roof over your head, and not worrying about your next meal--contributing your talent to F/OSS, regardless of who "benefits", is one of the best ways you can apply your specialized domain knowledge to improving the general good. Basically what the article says.