I wouldn't call this "the moral thing". If it was a setting as part of their spam filter that you can turn on or off, then maybe it should be permitted, but it should definitely not be the default.
Your question implied that no one needs to read mein kompf, thus proving that it's ok to censor it, thus showing that it's ok to censor anything else you don't like.
Since all of those things your attempt at a point stands on are false, the point in fact does not stand.
It's not only wrong, it's unbelivably ignorant.
Perhaps I'm misremembering from so long ago in 1979 or 80, but I feel like they explained the fundamental problems with censorship, including reasoning such as you present, as early as 4th or 5th grade.
That's why I say unbelievably ignorant. How is an adult saying something that a 5th-grader k ows better? I guess literally I can believe that they allow kids to reach adulthood without ever being made to understand something so important, but I sure don't want to.
I think you're being ignorant to the realities of modern communication.
Censorship of libraries and press in the pre-internet era is completely different than preventing new copies of stormfront being shoved down everyone's proverbial throat on a daily basis.