Forrest Cardamenis’s review published on Letterboxd :
No doubt many would blame the borderline-apathetic response to concentration camps seen in this film on technology - they take selfies on the gallows poles and with the "work will set you free" sign, for Christ's sake - but Sergei Lozintsa hit on a salient point in his Q&A: he stated that the problem is not that they are ignorant as to what went on, but that they know too much.
The Holocaust is now more than 70 years old, which is nothing in the span of history but is a lifetime in human terms. It's quite likely that many of the people here do not know anybody who died in the Holocaust or even who fought in World War II - they lack a human connection and cannot conceive of it in terms of anything but statistics and history.
The guides we hear also speak in a strangely rehearsed, unfitting way, and the mere fact that a memorial dedicated to millions of dead Jewish people and other victims (however proper its intentions) is a tourist attraction is already putting people in a mindset where they might make some unbecoming choices. Lozintsa also mentioned footage shot in 1999 at the same location where people acted more dignified and respecting, but 18 years ago the war was nearly a generation closer and overseas/intercontinental travel had still not taken off amid a wave of mass commodification of anything and everything.
It's too easy to scold the teens taking selfies - something else is at work.