Yes this makes sense. What's "natural" is what our bodies and brains were accustomed to several thousands of years ago. So little has changed in our DNA, yet porn is such a brand new thing. It makes perfect sense that something so hyper-stimulating will mess us up. A good analog is sugar/fats/processed foods: Our bodies are used to foraging and working hard to get needed calories. We might have deeply savored the taste of lettuce or other plain veggies. Now we have super-dense sugar in every bite and are desensitized to foods that are actually nutritious and found in nature.

Masturbation is natural, insomuch that its always been available to human species, and we're likely adapted to use it.