According to the article, the Chinese government was partially responsible for stopping this project, not start it to "increase the GDP."

Regardless, whatever China's economic strategy, it seems to be working quite well and not just "for a while." This project was started/abandoned over a decade ago and China is still experiencing close to double digit GDP growth every year.

Giving away free jobs or free money is actually not such a ridiculous proposition. If the recipients actually use that money, whoever they spend it on now just got more business and can in turn employ more people, who will use their paychecks to buy other things and thus continue the economic cycle. The public works jobs in the New Deal and the rebate checks in 2008 are a couple examples of this in practice in the US.