I feel it's mostly the confidence thing in every thing we do. If we believe something is so, no matter what scientific data proves, we are more likely to go the route we have the most cofidence in and subsequently have more success in doing so. Simply because we do it that way more often than the scientific way.
However, that does bring up an interesting point about deer urine. Is it deer urine or whitetail deer uriine? After you think about that comment awhile, what is your success ratio using the product you use. What is it defined as?