Because only small portions of people were rich and workers couldn't afford stuff they made and people went hungry.
Socialism is a system in which property and wealth are shared equally. Central to the meaning of socialism is common ownership. This means the resources of the world being owned in common by the entire global population.
Though Liberalism and Conservatism would remain the chief political ideologies in Europe during the 19th century, this period saw the emergence of another modern political doctrine - Socialism.
Socialism would influence much of the class politics of the late-19th and 20th centuries, and from the very first it was viewed as a threat by more traditional observers.
Socialism's most distinctive feature was its collectivist ideology, which contrasted sharply with individualism. Whereas Liberalism and many forms of Conservatism took the individual as the most important political unit, aiming to protect individual rights, Socialism was more concerned with bettering the political and social conditions of society as a whole.
Individual interests were not permitted to interfere with this larger goal. The Socialist attitude received some support from Pope Leo XIII in his Rerum Novarum of 1891, in which he decried the evils of modern capitalism and argued against the replacement of family and community loyalties with individual interests. This was a strong attack against Liberalism and laissez-faire economics.
Learn more about Socialism in America at U-S-History.com and UNLV.edu.