Moffatt himself might have been pursuing this in a casual way but the others at first were surely out just for a youthful grand adventure. The trouble with visions one has in solitude is that they are meaningless to anyone else unless you return to society to share your insight with others. Grinnell gets into trouble, however, and loses much of the sympathy that the reader feels for him. In the epilogue, he shows himself to be deeply cynical and bitter instead of being full of youthful optimism and hope. He launches into a diatribe against capitalism, modern agriculture, technology and academia.
Science is presented as inherently evil.
Charles Darwin is the toady of vicious racists. Franklin Delano Roosevelt, who practically invented income redistribution through taxation of the rich and became the champion of the disadvantaged through government social programs, is portrayed as a wicked capitalist exploiter. Grinnell's own Ph.D. from Berkeley is viewed as a means to disseminate lies and disinformation. What we have here is a severely depressed individual whose life has been tinged by tragedy. He is not trying to engage in a serious discussion of these controversial social, political and moral issues.