It doesn't matter why, really, unless you want to take a political stance that it ought not to be. Chalk it up to chance.

People who are addicted are looking for something that can't really be found in the thing they're addicted about. The addiction is just temporary fix for their dissatisfaction. It becomes an obsession partly because it is never enough, never really quite satisfying.

Your porn addiction is probably linked to a desire to love the kind of people shown in the porn, and even though there's sex drive involved there, there's also a desire to do good for people like that, make them happy, improve their lives. And to be loved and respected by them for doing that.

If you aim for doing that loving and helping stuff you REALLY want to do without getting into anything illegal, then you will find that the porn thing loses its power over you. You may always find those kinds of images arousing - men are visual by nature - but your yearning to give and receive human love will have other places to invest its energy.

Prayer about this helps.