Because you end up feeding a primate/reproductive prime control system, using unlimited and synthetic input. The system was never designed for the this kind of "bandwidth". Since we are biological machines, other parts of the organism need to compensate... This compensation is very dangerous in the long run both from a personal and a social side.
You could argue the same about entertainment. But seeking it is not a prime directive on an organic level opposed to reproduction.
I don't think the focus should be on "understanding what it is". Others eat ice cream and don't get into a physiological loop that they can't control without a lot of hardship and scientific tools.
> Yes. But given the choice, in non life or death situation. Between sex and food. People would pick way more sex than food.
Ever notice how folks have sex less frequently when they're in relationships and as they grow older? Where the opportunities for sex exist in multitudes? Yet they never stop eating. You can live without sex, you can't live without food. The drive for the two are not comparable.
You could argue the same about entertainment. But seeking it is not a prime directive on an organic level opposed to reproduction.