"Natural" doesn't mean good for long term

You see a lot of guys that only want to give up porn, since they view it as unnatural.

But they still want to ogle women, fantasize, have casual sexual, or even masturbate...... because they view these things as "natural".

Well, your limbic system drives you towards many things that are natural, but are NOT good for your long term health and happiness.

There is a small mammal that literally has sex until it dies. The males never live longer than one year.

http://www.iflscience.com/plants-and-animals/new-species-marsupial-has-sex-until-it-dies/

It is "natural" for these little males to do so, but it doesn't mean it is best for them long term.

An extreme comparison? Sure. But the point is that just because something may be biologically natural, it does not mean it is good for you long term