One variation of this flawed thinking is the argument that the validity of a proposition is to be judged by its effect on society. Interestingly, this was a favorite argument of communist theoreticians.
I don't doubt idea of homosexuality is so fervently believed that it is put into practice (and is even believed to be beneficial by some people) even though myself and the greater part of the population do not practice it. Is the idea of homosexuality "invalid." No. I did not use the quality of "usefulness" as a means of discrediting evolution in any other regard than the value of its usefulness on the face of it, not its validity as one philosophy of history among many.
I am grown up enough to understand that not everyone has the same philosophy of history I do. I am also smart enopugh to know the difference between science and philosophy, a point that seems to be lost on Judge Jones et al.