For context on that, Bismarck's abdication in 1890 left a leadership vacuum that was was gradually filled-in by military elites, who were more interested in the mechanics of warfare than the nuance of politics. Where Bismarck used military force as political tool, in his absence every problem began to look like something that only the military could solve.

Although, it's worth taking this opportunity to repeat: the same military elites responsible for the tragedy of WWI and the Dolchstoss myth were responsible for appointing Hitler into power and legitimizing his militant tactics. Hindenburg and Ludendorff created Hitler, from inside and outside the establishment, respectively.