"The South African government is responsible for the massacre because it had the political power to stop it from happening," he wrote in City Press.
He said that since 2008, the youth league had been the only voice speaking in defence of miners' interests and aspirations.
"How do you explain and justify the reality that rock-drill operators are paid as little as R4 000 per month in the mines?" he asked.
"How do you explain that mine workers reside in the type of conditions the Marikana workers find themselves in?"
He said when the league had raised these issues, President Jacob Zuma had ignored their concerns.
Malema said Zuma had assured mine owners and investors "that the South African government will not change the conditions of workers and will not change any policy with regards to minerals management".
The massacre could have been avoided through mining regulation and the appointment of a more experienced police commissioner, Malema wrote in the weekly.
Thirty-four protesting miners were killed at Lonmin's Marikana mine when police opened fire on the crowd on August 16.
League to march in Cape Town
Meanwhile, the ANC Youth League in Cape Town said it was planning to march to premier Helen Zille's office on Monday, according to a report on Sunday.
Zille told the Sunday Times she would only accept the youth league members' memorandum in person if it withdrew "their threats to make the city ungovernable".
ANCYL Dullah Omar region chairperson Khaya Yozi said the march was to ensure that "white beneficiaries" of economic production would "feel the pinch" but added that the aim was not to incite violence.
The protest was to draw attention to service delivery gripes, he said. – Sapa