It is wrong to judge revolutions by whether they succeed or fail. Virtually all revolutions fail. Either they fail literally and are reversed by forces of reaction or they fail metaphorically by compromising their lofty goals. The fairest way to assess the impact of a revolution is by the fact that it happens at all.
Michael Goldfarb, Emancipation: How Liberating Europe's Jews from the Ghetto Led to Revolution and Renaissance
fail-reaction, revolution, succeed