Fair enough.
But the guys who say "porn is not fine" likely live for and are scared of their girlfriends, trying to justify its not ok.
There is also no reason to get agitated if someone says porn is good for you, you can disagree as well without getting upset. I'm sure science hasn't done ALL the studies related the porn. They just do the studies on the "bad" effects of porn because its damaging to women. We have to protect women at ALL costs.
Porn could help men by allowing them to not value women so much. Porn could help men on how to have sex. Porn could help men relax when talking to women. Why they don't do scientific studies on these things? Because it doesn't affect WOMEN. The world revolves around what's good and not good for WOMEN.
I'm not for or against porn. You just have to look at BOTH sides of every issue.