Roosevelt, Pinchot, Muir, Marshall among others were wealthy individuals. No one would argue they were corrupt, in fact many would say they were some of the founding fathers of modern conservation. But they were civic minded individuals. They held a sense of duty to the places and critters they fought for, and to the people who would love them as they loved them.
I think the growing trend you allude to is at its core selfishness. A willingness to exploit and a self centered attitude, not just among rich folks, but amongst society in general. “Rich people” just have the means, and are therefore much more effective at making it happen for themselves. But not all are evacuated of morality.