Capitalism is antithetical to individualism. Capitalism replaces individualism with commodification. People are nothing more than units of production and consumption in the accounting of capital. Even the "masters" of capital are mere servants to the cancer of profit. Individualism is a threat to capitalism.
(Conversely, only with socialism can the individual be free to be him- or herself. See Oscar Wilde's essay "The Soul of Man under Socialism".)
human rights, anarchism