I disagree somewhat with the premise. Here is a quick breakdown in chronological order, sourced mainly from Wikipedia, numbers
as reported.
Majdanek
1,000 prisoners evacuated in July 1944. Presumably 10x more unreported.
Thousands of prisoners liberated on July 24, 1944.
The
Soviets' video submission to Nuremberg, reel 5, from timestamp 03:30, includes footage of the remains they found, including the excavation of naked bodies, a collection of skulls they (the Soviets) were building, bodies in the forest, the burned-out crematorium, and a pile of ashes.
Klooga
Partial evacuation in September 1944.
Only 85 survivors liberated on September 22, 1944.
2,000 bodies or partially cremated bodies were found, some of which appear in the same IMT video, reel 4.
Also see
this Klooga atrocity poster capitalizing on the same material.
Auschwitz
58,000 prisoners evacuated to other camps on January 17, 1945.
Remaining <9,000 prisoners liberated on January 27, 1945.
>600 unburied corpses found. Only a small number of bodies appear in the Auschwitz liberation footage (
reel 1,
reel 2).
Ohrdruf
>6,000 prisoners evacuated April 1, 1945.
Remaining prisoners liberated April 4, 1945.
40 bodies found in a shed, more found in an incomplete pyre and on the road and in the forest, with supposedly 3-6,000 more recently buried or cremated by prisoners.
Buchenwald
~7,000 evacuated April 6-11, 1945.
>21,000 prisoners liberated April 11, 1945.
Piles of bodies found outside crematorium.
Bergen-Belsen
Receiving site for many evacuees.
60,000 survivors liberated April 15, 1945.
13,000 unburied bodies found.
Dachau
>10,000 evacuated April 26, 1945.
>30,000 liberated April 28, 1945.
Numerous bodies found piled up in crematorium, which was rendered inoperable by lack of fuel, plus more in a train car.
In my opinion, the west and east camps were similar and were portrayed similarly at war's end. Not hugely different. Where they do differ, it results from three things: the date of liberation, the state the camps were in, and how the Allies chose to portray them.
That is, the eastern camps were liberated
earlier by several months, which meant they avoided some of the carnage caused by starvation and disease. They also had simply
fewer prisoners left by the time liberators arrived. Most of their prisoner population had in fact been evacuated west, especially to Belsen. When the western camps were liberated, they had several times the population of the eastern camps, so it shouldn't be surprising if they had several times as many deaths.
Lastly, the western camps were part of a deliberate propaganda effort, which Eisenhower admitted to, as shown
here. Ohrdruf was a small camp of no particular importance, but it was seized on by Eisenhower and his underlings because it was their first opportunity to photograph and film corpses. Chiefly for propaganda reasons. The other western camps followed, but at that point it was mere repetition. And it's important to point out that the eastern camps, in their worst parts, were also used for propaganda, it's just that the Soviet propaganda is less familiar to us in the Anglosphere.
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Still, none of this gets to the essential question: why do the supposed extermination sites not look the part? This will remain unanswered.