Capitalism was probably never self-aware of itself enough to have any intents as it evolved. The idea of putting money to work for a return goes back to before the Roman Empire - it's pretty much the same idea everybody thinks of as soon people start using money in commerce. The ideas about how to run a business to most efficiently exploit everyone and everything else are more modern, but I would almost be tempted to separate the general framework for the generation of production by private investment i.e. capitalism as framework for economic activity, from the creation of economic regulatory structures that allow for so much exploitation in the name of profit. The first is a matter of economic theory, the second is simply a matter of political failure in a society.
You can have, and we have seen, terrible human and resource exploitation in both capitalist and non-capitalistic systems. That is always more a matter of governance, politics and how power is distributed in a society than of economic models.
In the recent history of the US, when the law was friendly to unions, workers had more power, worker exploitation was lower. Today the legal environment has been made more hostile to unions and workers, workers have less power, worker exploitation and economic disparity is greater. It wasn't that capitalism somehow changed, the governance under which the US instance of capitalism operates has changed.