One dictionary that I consulted remarks that "natural history" now commonly means the study of animals and plants "in a popular and superficial way," meaning popular and superficial to be equally damning adjectives. This is related to the current tendency in the biological sciences to label every subdivision of science with a name derived from the Greek. "Ecology" is erudite and profound; while "natural history" is popular and superficial. Though, as far as I can see, both labels apply to just about the same package of goods.