The criticisms of capitalism, at least from a scientific standpoint, are not that people under capitalism are doing bad things, it's either that (i) under previous or potentially future modes of production there would be little or no incentive to do those things, (ii) capitalism has exacerbated the degree to which the behavior persists. The second part of the criticism is that capitalism is a class society, and thus rife with the antagonism that comes with class society in the form of "contradictions", which manifest themselves in capitalism as the contradiction of abstract and concrete labour, use-value and exchange value, capital and labour, price and value, culture and the commodity etc.
The modern middle-class society of the present day would quite simply be utterly unrecognizable to 19th-c. theorists of "capitalism [as] a class society". In fact, they would find that most, if not all, of the policy goals that they originally set for themselves have been achieved, in a market economy! The Chinese leadership understands this quite well, BTW; the above consideration plays a significant role in their understanding of what a "socialism with Chinese characteristics" should look like.
So? What came before capitalism? Feudalism. That was a class society at least as much as capitalism is.
More like 15th century, is the widely accepted chronology. And it did bring with it a totally different kind of horror, including colonialism...
(China could have had an iron-based industrial revolution long before Europe. But the mandarins saw that some lower-class people were getting rich, and so they shut it down by force.)
Also: Colonialism is an evil of capitalism? The Roman Empire did something very like colonialism. The Spanish in the 1500s weren't exactly capitalists, either.
