I think the title says it well enough. I know the Italian revolt failed because France helped the Pope, but what about all the others?
From Jonathan Sperber 'The European Revolutions, 1848-1851'
-Revolution was heavily romanticized, revolutionary leaders often portrayed doing heroic deeds for the people. Lajos Kossuth from Hungary riding out and rallying peasantry or Giribaldi leading militias into battle.
-Some revolutionaries were incompetent and monarchs did not always take them seriously.
-Failed to establish lasting regimes. Old rulers took back power later on.