Durin did not extend his hand.
The romantic spirit of the youth could make them forget their suffering, view sacrifice as the best recompense, to the extent that they forgot that this filthy world was not worth cleansing with their blood, not worth sacrificing their lives for.
Durin had seen too much injustice—most of the wars in history were merely the antics of some age-old beings fighting for resources, power, and land.
Like in the First World War, millions of young men fought for their respective countries, and their youth fell in each other's pools of blood, many dying for the empty promises of those age-old beings.
They were sons from good families, yet they died for the greed and desire of others.
Durin did not fear sacrifice, but he feared for his brother, feared for these young people around him—the greatest phoenix rising from the ashes was not non-existent, but so rare that Durin considered the Northern Doctrine not worthy of being called great.