No it's protecting children from people who feel encouraged to live out their fantasies because there is media that depicts children in those situations. The argument is that allowing content like that normalizes the behavior and so the mods are trying to curb that behavior. [snip]
Let me clear a couple of things up before the main point.
1. I don't think that other guy was making that argument himself, he was sarcastically quoting their oft given phrase.
2. I very well could be wrong on this, but I believe the reasoning behind rule 7 is simply to protect the site, not the mods' own personal vendetta. I don't want to put words in their mouth either way but I recall reading a few things that mirrored that sentiment. As such, while valid (and I share your sentiment), there's nothing that complaining does that hasn't been said hundreds of times before and will continue to be said albeit to a stone wall.
The main point I wanted to address, and I acknowledge it's slightly off topic but still important, is that in fact all data points to the opposite of your claim of normalizing. Simply put, access to pornography decreases incidents of sexual assault. It's just the implications of this make people uncomfortable so they choose to ignore it.
There's a decent write up on the history of it here if you care to read:
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