For the same reasons as he once “believed in” Freudian psychiatry, according to Laszlo Bencze:
Freudianism triumphed (for a while) not because of its scientific value but because of its language. Freud was a high grade intellectual fully immersed in the ancient classics and literarily sophisticated. He used the language of writers, artists, and critics in crafting psychoanalysis. When people read Freud they were exposed to unusual ideas in language that felt like an old shoe. An ex British schoolboy who had struggled with Latin and Greek felt masterful in encountering discussions of the Oedipus Complex. It flattered him to know that his literary wrestling matches had finally paid off in deep understanding. There never was anything truly demanding in Freud. No math. No statistics. No biochemistry. No charts or graphs. All it consisted of were the sorts of literary insights that any bright student might have stumbled upon in a study of Hamlet. As Karl Popper pointed out, Freudian insights were nothing but a string of “just so” stories that could explain any type of human behavior.
…every conceivable case could be interpreted in the light of Adler’s theory, or equally of Freud’s. I may illustrate this by two very different examples of human behavior: that of a man who pushes a child into the water with the intention of drowning it; and that of a man who sacrifices his life in an attempt to save the child. Each of these two cases can be explained with equal ease in Freudian and in Adlerian terms. According to Freud the first man suffered from repression (say, of some component of his Oedipus complex), while the second man had achieved sublimation. According to Adler the first man suffered from feelings of inferiority (producing perhaps the need to prove to himself that he dared to commit some crime), and so did the second man (whose need was to prove to himself that he dared to rescue the child). I could not think of any human behavior which could not be interpreted in terms of either theory. It was precisely this fact—that they always fitted, that they were always confirmed—which in the eyes of their admirers constituted the strongest argument in favour of these theories. It began to dawn on me that this apparent strength was in fact their weakness. —Conjectures and Refutations, Karl Popper, p. 35
The power of evolution is also in its language. Darwin knew nothing of population statistics or the intricacies of replicating DNA. Nor do most proponents of evolution today. Just as in Darwin’s day, the power of evolution lies in how “obvious” its conclusions are when expressed in normal, conversational language. There are many similarities between monkeys, apes, and men. Therefore it’s obvious that some sort of ancestral relationship must exist. Offspring differ from their parents in certain visible traits. Therefore it’s obvious that beneficial traits will be favored in the population and eventually lead to new species. It’s obvious that a personal god who can willfully interfere with the events of the universe does not exist. Therefore, it’s obvious that the driving force of evolution can only be randomness. Once again, there’s no math, no statistics, no biochemistry in any of this. Further, when any of those studies get applied to evolution, they all happen to disprove it. But that doesn’t matter to the popular mind because the “obvious facts” so well explained in popular language by evolution proponents trump any technical criticism.
It’s the sort of truth that TV talk show hosts love: truer than facts and much more earnest and salable.