In the last mini-lecture on a marxist critique of capitalism, I listed some of the more positive effects of capitalism on a number of most important human needs and human concerns.
Capitalism tends to disemploy people.
Capitalists in a quest for both profits and effficiency, try to lower costs and increase production. Capitalism tends to economic crisis. Another way to think of the immiseration thesis and the points above is in the tendency of capitalists to 'externalize' costs. I would anyway.