80 Years Since The Great Terror, Its Historian Is Under Prosecution

Yes, unfortunately, the Great Terror is not that well reported. However, it is one of the most tragic moments in the history of former USSR, comparable only to World War II. It was, of course, never reported during Stalin's lifetime (till 1953), and some information only started to be published in the 60s, when some prisoners started returning from GULAG.

But then again, the picture was distorted, because reporting Stalinist crimes in full would implicate many members of the party elite that was then in power (starting from Khrushchev himself), and they, of course, would never prosecute themselves. So the scale of the terror campaign was diminished, and the guilt was shifted from Moscow to the local governments and the people who wrote "3 million denouncing reports". So it wasn't until the late 80s and 90s and the opening of secret service's archives that truthful reports started to emerge. By that time, most eyewitnesses of the Great Terror were dead, many documents were lost. And the Russian government never really encouraged such efforts, turning the whole thing into the unspoken (and untreated) trauma.