The Paleo Diet is effective for most people at adipose tissue reduction and health and fitness improvement. The problem is that effective does not mean optimal, nor does it imply that the underlying concept is absolutely true.
Lets look at it another way if you put someone on a diet that includes whole food sources, is high in nutrients dense and low calorie foods would you expect them to improve across most parameters compared to the average diet. Of course almost all sensible diet perscriptions are based on those principles. Once you decide on one such strategy and find it works for you it is is easy to look back and decide that the rationalization behind the diet must be true.
The problem is we know based genomic work that the Paleo hypothesis is false. We are not unchanged from 10,00 years ago, this should be obvious, there are two seperate lactase persistance genes that have swept to nearly universallity in specific populations within the last 6,000 years. Salivary amylase production has been upregulated in populations with history of starch based diets. Even the gluten itolerance often used as argument for paleo diet may turn out to be a pleotropic effect of a neolothic adaption to increased immune defense.
It appears that populations with diets based around meat carry metabolic adaptions lacking in agricultural populations as well. Though this is fairly new topic of research
Tthe paleo assumption is untenable and in order to really optimize diet we have to understand the post paleolithic evolution of human metabolism and the differences between different populations and individual. Paleo is a nice story but your not grok and what is best for you may not be the same as what was best for him and may not be what is best for the next person either.