My bumper-sticker answer is basically that paleo proposes some of the right things but for the wrong reasons.

Avoiding processed foods and refined sugar is good. Avoiding dairy is good. But there's no reason in general to avoid cereal grains, legumes or potatoes unless you're sensitive/allergic.

And higher-quality meat is an improvement over the status quo but a vegetarian diet is likely to be healthier.

But all that is me talking, not my wife. I suspect she would say similar things but honestly we don't spend a lot of time discussing the random fad diet book du-jour.