"Is there something about Heidegger's formulation, with its longing for a return to a premodern way of being, that necessarily sets us on the road to Treblinka?" The answer is yes. The romanticization of the pre-modern world is primarily based around a rebellion against the 'mob'. Rather, such philosophies posit the philosopher and their like-minded kin as some sort of intrinsic elite. Whether you define this elite as blooded nobility, those who attended the right sort of university, or merely those of a some sort of Aryan race, the basic concept of elitism de-humanizes the rest of humanity. Rather than being people with equally valid goals and desires, they become merely servants to your whims - to be exploited or disposed of as best suits your needs.

On the other hand, it doesn't necessarily follow that they are wrong to do so...

"On the other hand, it doesn't necessarily follow that they are wrong to do so..." Unfortunately, they usually are. The difficulty is those best suited to acquire power are normally the least suited to exercise it - it requires an enormous degree of arrogance and narcissism to actively seek power. And those same qualities lead to poor decision-making for others unless checked.

"such philosophies posit the philosopher and their like-minded kin as some sort of intrinsic elite. Whether you define this elite as blooded nobility, those who attended the right sort of university, or merely those of a some sort of Aryan race, the basic concept of elitism de-humanizes the rest of humanity. Rather than being people with equally valid goals and desires, they become merely servants to your whims - to be exploited or disposed of as best suits your needs"

Science, technology, the arts, philosophy, all these pursuits depend on elites. Egalitarianism will give you the lowest common denominator, not excellence. This being so is nobodies fault and nobody is at fault being better at what he does than others. This is not to be confused with elitism.