I tend to agree with you that because porn covers a very, very wide range of material and target audiences, universally condemning it is too much of a generalization.Junk food still provides nutrition and energy, and alcohol does have actually have modest benefits including stress reduction; in small amounts it MAY be a net benefit to consume it. You can also make the case that many drugs have benefits that outweigh the costs.
Porn itself is not bad (especially pre-internet porn) but our modern high speed, streaming, free internet porn is inherently harmful and toxic by nature.
Also, porn is absolutely comparible to hardcore drugs in terms of its devastating effects on the brain. There are neurological studies proving it; that wasn't merely a statement I made for the sake of argument.
Looking at some titty pics is not the same as some of the gross sh!t you can find online.
Drinking a glass of red wine with company is not the same as chugging vodka for breakfast.
Eating a cheeseburger after a long hike to replenish calories is not the same as being 600 lbs.