Billionaire Jack Ma again encouraged tech workers to embrace the industry's extreme-overtime culture, defying a growing social media backlash.

The Alibaba Group Holding co-founder once more endorsed the sector's infamous 12-hours-a-day, six-days-a-week routine as de rigueur for passionate young workers. In a lengthy Sunday blog post, China's richest man expanded on comments from last week, in which he dismissed people who expect a typical eight-hour office lifestyle.

"As I expected, my comments internally a few days ago about the 996 schedule caused a debate and non-stop criticism," Ma wrote. "I understand these people, and I could have said something that was 'correct.' But we don't lack people saying 'correct' things in the world today, what we lack is truthful words that make people think."

Ma's earlier comments stoked a fierce ongoing debate over tales of programmers and founders dying from unrelenting stress. Chinese tech workers protested labor conditions on the online code-sharing community GitHub in March under the banner 996.ICU, which quickly became the site's most popular topic. The term 996 refers to a 09:00 to 21:00, six-day a week work schedule.

Beyond Ma, several of China's most prominent industry figures have also weighed in on the controversy. Richard Liu, chief executive of Alibaba arch-foe JD.com Inc., said in a recent post on his WeChat moments that, while he would never force staff to work a 996 schedule, people who slacked off were not considered his "brothers." On Sunday, Ma said forcing employees to work gruelling hours was "inhumane" -- but that some wanted to do so.

"Those who can stick to a 996 schedule are those who have found their passion beyond monetary gains," Ma wrote.