And despite his founding of the Intercept in part to investigate abuses by people in power (and his constant criticism that the press never publishes negative articles about people on their side) he has never written a single article critical of any of the abuses of power by the Trump administration. Not a single article critical of anything Trump has done in the past four years. [1]
1. All articles: https://muckrack.com/ggreenwald/articles
I think you're grossly misrepresenting his opinion on the matter. No one denies that Russia made some half-assed attempts to influence the election. Every country tries to interfere in every election. Hell, we even bragged about it at times: http://content.time.com/time/covers/0,16641,19960715,00.html
Even Biden himself brags about interfering in the affairs of other governments: https://youtu.be/FdHWU5jDQ2w?t=46
But did Russia conspire with the Trump campaign to rig the election or provide dirt on Hillary Clinton? No, and he's right for standing by that claim despite the immense pressure from partisan hacks who have effectively smeared him as some kind of Russian puppet. Your post is evidence of how effective that smear campaign has been.