In the states, where at least a quarter of the target audience lives, and probably 1/3rd (guessing on these numbers) of the coders are employed, it's a culture based thing. To an extent, that very culture extends to (some places of) Europe. It's very much based in the bible. Teachings based on feeling ashamed of our naked body are indoctrinated into our society, and make its way into our subconsious. We operate this way because it's coded to be this way. Hundreds of years of biblical doctrine have taught us; be shamed of your naked form.
Now, some people like myself are not ashamed of their naked form. (No, I'm ashamed of the splotches on my skin, the 2 pack abs, and thighs that scream, "No, not the bathing suit!") I draw naked people all the time for my studies in art/design. The naked body is both beautiful and repulsive at the same time, but nothing to be shamed about. I also abandoned my religious upbringing.
There are many evangelicals (not sure that's how it's spelled) that get offended at the sight of nudity. It's a moral depravity saved for the privacy of ones own residence. These guys are tuned- not into the subconsious indoctrination biblical influences have had on us for centeries. No, these guys are hooked into the source!
Between biblical indoctrination and people who actively practice the teachings of the bible, we're kind of stuck in a place that frowns on nudity. Culture is shifting in the west, as it often does. We can swear more liberally on TV, and sexual themes aren't quite as taboo as they were say, 30 years ago. But for the time being, anything that tries to break pace of social shift will be shocking.
To address what the bible says about violence; in a nutshell, it's bad. But war is necessary at times... but it's bad. It's a violent book that contradicts itself a lot, but that's a highly volatile discussion for another day.