It is a legitimate known translation, not a misquote from the Ralph Manheim translation of Mein Kampf (ISBN 0395078016 / year 1943), page 403. Other translations have similar wording on the page, although not in such a nice succint sentence.
Manheim was known to have gone into great effort to create an exact English equivalent of Hitler's work for Mein Kampf.
> It's also a morally horrific line of argument. Like saying you shouldn't care about shooting civilians because bad people in the past have used human shields as a war tactic.
The point of the quote is to show there are no limits curtailing liberties, not an absolute we shouldn't bother. The attempt to spin the quote into something else, probably because, you wish to "protect the children" is proving the point.