Perhaps you should review the short Prussian reform era. Conscription had to be enforced in parts of Prussia in 1813 with troops because it wasn't popular (Theodor Korner remarked upon that problem). And the reforms and reformers themselves were out of favor by 1814-1815 as Frederick William didn't need them any longer. He got what he wanted-territorial aggrandizement to increase his kingdom. Why do you think there were subsequent upheavals and at least one revolution in Prussia after 1815, and elsewhere, in the 'period of peace' after the Congress of Vienna?
Political and dynastic reaction set in with a vengeance after Napoleon's fall and that set the tone for political problems and restless populations. And it wasn't because the monarchs were 'benevolent.'