That was my interpretation of the explanation in the comment I replied to.
Scorched earth is what Russia does. Peter the Great had used it to repel the Swedish invasion during the Great Northern War. Napoleon himself had studied that invasion and tried to learn from it. Instead, he repeated the failure of Charles XII on a larger scale.
Napoleon himself had faced scorched earth in Portugal during the Peninsular War a couple of years earlier. It was effective.
In other words, Napoleon knew that Russia had a habit of using scorched earth, and he knew that it was effective against his forces. The reasonable assumption was that Russia would use it again.
Also, Moscow was not the capital, and Napoleon had already lost the majority of his army before reaching it.
Scorched earth had lost most of its military significance by WW2. The USSR tried it in 1941, but it failed, because trucks had revolutionized warfare. They could transport food over long distances, allowing armies go to places where they previously couldn't and stay there.
In 1812, Napoleon suffered huge losses in the first weeks of the invasion, before fighting a single major battle. His army could not find enough food in Russia. In 1941, the total number of Axis military deaths during Operation Barbarossa was comparable to what Napoleon suffered in those first weeks, despite many battles and much larger scale. When the invasion failed, the troops mostly just stayed there and tried again next year.
Scorched earth is what Russia does. Peter the Great had used it to repel the Swedish invasion during the Great Northern War. Napoleon himself had studied that invasion and tried to learn from it. Instead, he repeated the failure of Charles XII on a larger scale.
Napoleon himself had faced scorched earth in Portugal during the Peninsular War a couple of years earlier. It was effective.
In other words, Napoleon knew that Russia had a habit of using scorched earth, and he knew that it was effective against his forces. The reasonable assumption was that Russia would use it again.
Also, Moscow was not the capital, and Napoleon had already lost the majority of his army before reaching it.