Yes it is an emotional argument. I used to work somewhere with content moderation. From my conversations with people on that team, the effects in this article are spot on, and I would argue are damaging. Maybe not catastrophic but journalists gotta make bank too.
Think of the disgust or shock you might feel if you saw, say an adult flirting with a kid, or if that’s not graphic enough, having sex. Now imagine you need to see that every hour or so for your job, 5 days a week, forever. There’s no end, there’s no stopping people.
At best you lose some of your humanity and innocence - nothing really shocks you any more. At worst it causes some form of PTSD or you even sympathize with what you are seeing. I can see how that could be less painful in short term than continuing to be shocked and depressed with things you don’t agree with.