Why is that website to be trusted as accurate over the statements of a genocide scholar that specifically studied the Soviet government of the period about their atrocities?
For the holodomor, snyder gives a figure of over 5 million deaths, which is much too low. The best study on this matter comes from oleh wolowyna, who concluded that over
7.6 million people died in the famines.
For the gulags, snyder gives a figure of 1 million deaths. The minimum accepted number is actually
1.6 million. Thats what the NKVD themselves said after the war, and you can bet that they were giving a low number!
So tally up the number of deaths that occurred during stalins reign, in roughly chronological order:
7.6 million civilians killed in the holodomor
390,000 kulaks killed during relocations
750,000 to 1 million prisoners killed in the purges
100,000 to 150,000 polish POWs killed
130,000 to 320,000 polish and volga germans killed during relocations
380,000 to 1 million axis PoWs killed
140,000 chechens and inguish killed during relocations
1 to 2 million axis civilians killed during occupation
1.6 million prisoners killed in the gulags
So even if we ignore the multitude of smaller massacres, and use the smallest number possible for the gulags, stalin is clearly responsible for anywhere from 12 to 14 million deaths. Robert conquests figure of 20 million deaths isn't nearly as far fetched as we would like to think.
It looks like the books they are citing came out in the 1990s before much of the documentation about the Soviet records had been discovered; prior works (early 1990s and before) were laden with Cold War propaganda. Conquest's book was written deep in the middle of the Cold War right after De-Stalinization tried to make Stalin look as bad as possible. I mean Stalin was a PoS, but we have to disaggregate what is real, what is propaganda, and what is myth and what is even reasonably attributable to Stalin specifically. Snyder makes the point in his article that it can be very hard to neatly categorize deaths in the column of one or another dictator during WW2.
Robert conquest actually wrote two books, one in 1969, and one in 1992. In the first book, he stated that stalins kill count was a minimum of 20 million, and probably more like 30 million. In the second book, he had come to the conclusion that 20 million was the most likely number of people murdered by stalin.