They have decided to not appeal to fringe geeks and nerds but to instead appeal to the affluent mass market in order to meet their moral responsibility. That moral mass market would prefer if "porn" was not readily available on their consumer electronic devices.
I hate to hit you with this, but the overwhelming majority of the population, both male and female, consume porn to one degree or another, and it is the "moral" minority who consume it more voraciously than normal, healthy people who don't hold fucked up bronze age beliefs that sex is bad. (Amusingly, online porn purchases slightly decrease on Sundays.) The market Apple is appealing to isn't moral, it's just hypocritical, not unlike the stridently anti-gay politicians who frequently turn out to be gay themselves.
The majority may claim to be above porn, but this is the same majority who also claim to be above masturbation, contrary to every reputable study ever conducted, which finds that non-masturbators are a tiny minority, especially among men.
_YOU_ may not like that but Apple's shareholders, to whom Apple answers, likes it quite a bit.
Sounds like you like it. I rather expect that most of Apple's shareholders will like anything that increases their profits. If that happens to be Steve Jobs' messiah complex, so be it. If, on the other hand, they thought there was a good way to monetize the iPhone's use to tap into the multi-billion-dollar porn market without hurting existing iPhone sales, then it would be Apple's moral responsibility -- your words, not mine -- to devote considerable resources to making sure that fisting videos were available with the tap of a finger, now wouldn't it?
But that's how morality goes, isn't it? Any time you hear someone talking loudly about it, you can bet you're dealing with a hypocrite.