How difficult is it for the OP to take on the responsibility of discussing the Holocaust with their 11-year-old; apparently quite difficult. That's where the problem lies with our youth. It's not the schools, the teachers or their peers that don't get it; it's the parents that just don't get it. The lesson learned about Apple not taking control of their customer's reviews would be what? Once you determine what answer suits your immediate needs, then somehow YOU have to translate that to your 11-year-old; what, you expected Apple to be responsible for "the lesson learned?"
Asking Apple to invoke a method of censorship will accomplish nothing. My son would wear a T-shirt to the Big Game (Cal v. Stanfuurd) over the past (15) years that stated "F*#K Stanfuurd" and I would cringe each time he would wear it or buy a new one to replace the tattered T-shirt. I would give my last dying breath, to allow him the opportunity to wear that shirt in public or wherever he deemed fit. The shirt may be offensive, but those that find it offensive can turn a blind eye and continue marching; the shirt is not obscene, it is not pornographic and not provoking in the manner of fighting words; and therefore meets one or more of the Free Speech exemptions. Redirect your son's attention, block the website, or counsel your son as you see fit. Apple has no responsibility whatsoever to resolve or remedy your concerns. So, good luck addressing the issue of censorship with Congress, the Executive Branch or the Supreme Court; it's a definite "no-go!"