Some people have problems with it, but I see it on the same level as alcohol, video games or sugar. If you do nothing but sit in your room and eat sugar all day, you're not going to be very healthy.
The real question here is why so many people feel compelled to sit in their rooms all day and watch it... and I don't think it's because they have a personality issue, which is mostly just an excuse to prescribe drugs. I also don't think it's because the porn itself is inherently evil or wrong or addictive. I think it's part of the overall influence of technology on society, the fact that nobody actually cares what it's doing to us psychologically, emotionally or even physically, and the only concern is how much money it makes, how it feels at the time, or whether or not everyone else is doing it.
Porn has been readily available for most of recorded time if you include drawings, but it was never the scourge of humanity until so-called Christian groups and politicians looking for issues got involved. Maybe part of the problem is that it's now available all the time and you can sit in a room and isolate yourself with it without having anyone judge you or tell you to stop. So is that the fault of the porn, the individual or the technology?
Blaming the porn means people get to keep their devices, keep up their internet habits, and maintain that they are still 'good' people who have fallen victim to a 'dirty' industry that has stolen their souls. But nobody seems to question whether or not the Internet and computers are a serious negative influence on the human race, and nobody complains about that because it's gotten so ubiquitous so quickly and within about a decade it has gone from sort of nerdy or ridiculous or embarrassing to pretty much taken for granted.
Without a connection you're pretty much lost, so it doesn't really shock me that most of the normal activities like socializing, sex, entertainment, games, etc... are now online or computerized as opposed to real, and that this is causing a lot of problems. I see porn in the same light as Facebook, or tumblr, or any of those other sites that steal your time in nibbles, isolating you in a web of short blurbs that keep coming and coming and mostly just leave you in a fog afterwards.
Whether it's information, sex, entertainment or images... the end result is the same, the difference is that sex is demonized by puritanical, westernized societies and is more likely to be treated as shameful or sick.
I'm not defending porn-- but I really don't think that it's the biggest problem. I used a lot of porn when I was single, but now that I'm not, I hardly watch it at all. It was easy to give up when I had other things to do, and found someone who actually cared about me. But I still waste a shitload of time online.