Communist like systems where there is central control of resources encourages corruption as people vie to get closer to the central control of the resources

Communists advocate for immediate recall elections, and units forming syndicates that send delegates. Communism is designed against corruption.

Capitalism is just more honest about the fact that many people - not all of them - are fundamentally self-interested and entices them into cooperation with others by offering the carrot of individual rewards

Capitalism isn't honest nor deceitful, it's just a Mode of Production. Capitalism doesn't have a face or a will.

Those are probably the same people that would try to exploit the system if it were more centrally controlled.

What's considered natural depends on the Material Conditions, ie the Mode of Production. Capitalism reinforces greed by rewarding it systematically, Communism and Socialism do not.