Thanks to a sustained effort of decades by Gramscian Socialism and Hollywood, the modern American woman, on average, simply is not a very pleasant person to be around. Exceptions occur, but they are becoming ever more rare. Men are little better, but usually suffer less from deliberate conditioning than from neglect.
When a modern American man meets a woman from a more traditional cultural background, however, traditional results rapidly occur.
Men don't prefer porn to women in general (who would?) - they prefer porn to the defective products of the Welfare State currently dominating the American dating marketplace.
We have a very sexualized society. It's how we market things. It's why the weather girl on TV is always cute. It's why music has become what it has become. Again, porn is part of that trend, but is not the sole cause of the trend. I think Gramscian Socialism is, indeed, a much better guess at why this got started.
And although society is highly sexualized, feminism and PC norms have made normal male-female interaction very problematic. Dating in college? I don't think I would. Most (not all) of the women I know are harpies -- demanding, angry, sullen, "victims" and really annoyed that they can't find a decent guy.
It's bad out there. It's bad for a lot of reasons.
Porn is a bad refuge from it all, but not a terribly surprising one.