The idea that people who are healthy, secure, and mentally resilient don't tend to have crippling addictions is not terribly controversial. If a user is peddling it as scientific fact without any sources to back it up that is one thing. But this is a discussion forum not an academic community or professional society.
Saying trauma or other forms of adversity may be driving porn addiction is not the same as diagnosing people with psychiatric disorders online. We are allowed to speculate and discuss what drives human behavior, especially when the behavior is relevant to the entire thread. That's a lot different than saying things like "you obviously have ADHD" or "everyone with porn addiction has untreated PTSD." GP was not diagnosing anyone, they were proposing a mechanism that could be driving a particular kind of behavior.
If you google "trauma, adversity, and addiction" you will find a wealth of resources discussing scientific evidence of a connection. This is not all that controversial. I imagine the one group that would be most against this line of inquiry would be the subset of heavily moralistic people who use emotional and/or physical abuse to spread their worldview. See: Scientologists.
Finally, as an aside, there is evidence that epigenetic changes from severe trauma are passed from parents to their children. While I'm sure the majority of past-life trauma analysis is charlatanism, it is not as though we do not inherit some of our hang-ups and quirks on a biological level based on the lived experiences of our ancestors. [1]
Although this first article is only discussing changes to genetic expression, and not changes to the genome (mutation), there is also some evidence that epigenetic changes can lead to permanent changes to the genome under the right circumstances. [2]
[1] - https://www.scientificamerican.com/article/how-parents-rsquo...
[2] - https://www.the-scientist.com/features/do-epigenetic-changes...