Yes, people don't have control over what they type. They can't help it.
Do I wish that the level of discourse on the internet was higher, but however much I may wish it, I don't expect others to conform to my wishes. If it offends you and you are unable to ignore it, as most people do when something offends their sensibilities, then don't read the thread, or go elsewhere.
Your whole argument rests on the fact that other people lack self control of some kind. If making personal attacks aren't acceptable, for example, then people made a decision to not accept that behavior. Why can't references to "gang-bang" also be deemed unacceptable?
Most people understand this fact and thus ignore whatever offends them rather than express their objections.
The people lack self-control argument so never say anything. I hope you read what you type.
The first thing I think of when I read of people being "banged," is that they are being hammered, pounded, physically struck, not that they are being "raped."
The word wasn't "banged". It was "gang-banged".
I am sure when people read "gang-bang" they think of a car being banged in the parking lot.