You have to take into account Soviet intent. Stalin was not interested in liberating Poland or the other countries occupied by the Nazis per se. Stalin was interested in Soviet domination. He had already tried to conquer Poland in the Polish-Soviet War of 1919-1920 (in which Pilecki fought, as the article mentions). They lost to the Poles. The Molotov-Ribbentrop pact was essentially a temporary agreement (that really, neither the Nazis nor the Soviets intended to stick to ultimately) that explicitly had as its aim the division and dismemberment of Poland between Germany and Russia. "Soviet liberation" may mean that the Soviet occupation of Poland and the countries of the Eastern bloc had the result of removing the Nazis, but the ultimate goal was not liberation but also occupation.
That many Russians died to secure Soviet control over Central/Eastern Europe is not proof that the Soviets were self-sacrificial liberators, but rather that in Soviet, and ultimately Russian, culture, human life is much more dispensable to those in power than it is in the West. The Tsars, and their Soviet successors, were tyrants who could decide the fate of any subject. To this day, the Russian leadership has no problem in carrying out assassinations of politically problematic people, even abroad. The Soviet-installed government in Poland following WWII operated according to similar principles and under Soviet directives, though not to the same extremes as the Soviet leadership. Pilecki is one of many who were brutally tortured and executed by the communists, many of them members of the Home Army. Both Nazis and Soviets took part in exterminating swathes of Polish society they saw as a threat or an inconvenience to their rule (e.g. Katyn massacre), during and also, in the case of the Soviets, following the War.
"ut rather that in Soviet, and ultimately Russian, culture, human life is much more dispensable to those in power than it is in the West."
It is easy to lay blame at the feet of a handful of leaders and forget that in centuries the Russian people put their arms, their strength, their blood behind such. It is easy to focus on a single tiny person within the scope of history and say of course this person had no power and no complicity in evil and forget that the totality of the Russian people are complicit in the actions of their leaders.
At the time of war there is no such thing as freedom. You are given a rifle and ordered to kill. If you disobey, you are killed, it's as simple as that. Try to be in that situation and then talk about responsibility.
Tell me, who was responsible for the hundreds of thousands killed in the battle of Verdun: individual soldiers? Scared to death, trembling, half-insane, playing dead under the dead, left without any reasonable choice, resembling more animals than humans? Or someone else, who actually sent them there?
Their society found their situation tolerable. Even after the chaos was over they kept the same style of leadership. The same people who spent their blood but kept their lives didn't fight for something much better.
That many Russians died to secure Soviet control over Central/Eastern Europe is not proof that the Soviets were self-sacrificial liberators, but rather that in Soviet, and ultimately Russian, culture, human life is much more dispensable to those in power than it is in the West. The Tsars, and their Soviet successors, were tyrants who could decide the fate of any subject. To this day, the Russian leadership has no problem in carrying out assassinations of politically problematic people, even abroad. The Soviet-installed government in Poland following WWII operated according to similar principles and under Soviet directives, though not to the same extremes as the Soviet leadership. Pilecki is one of many who were brutally tortured and executed by the communists, many of them members of the Home Army. Both Nazis and Soviets took part in exterminating swathes of Polish society they saw as a threat or an inconvenience to their rule (e.g. Katyn massacre), during and also, in the case of the Soviets, following the War.