Laissez faire does not mean: let the evil last. It means: let the consumers, i.e., the people, decide - by their buying and by their abstention from buying - what should be produced and by whom. The alternative to laissez faire is to entrust these decisions to a paternal government. Theres is no middle way. Either the consumers are supreme or the government.

Ludwig von Mises (1946), Observations on Professor Hayek's Plan, Libertarian Papers 1, 2 (2009), 2.