system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Why aren't Slytherins's open use of blood prejudice challenged by students, some whom lost their family to Voldemort?

While it's understandable for the corrupt Fudge to let Lucius bribe his way out of prison, why would Hogwarts students, some of them lost their entire family to Voldemort & Death Eaters, allow Draco walking around spouting the very same hate speech that killed their family? It should be like in Durmstrang where edgy students drawing Hallow's symbol are 'taught the error of their ways' by Grindelwald victim's family.
gpt
The truth of the matter is that there is a lot of tacit support for ideals of blood purity among the wizarding population, even at high levels of society and government. It might not be the majority, but it's enough to pose a threat. Even though the Order and its supporters won the last war, Voldemort's supporters and fellow travelers didn't really meet with a whole lot of punishment (with a few exceptions), and many of them (like the Malfoys) continued to hold positions of great influence even after openly working for Voldemort. This means that the pro-Muggle people have to be careful about coming down too hard on the blood-purity types, lest they upset the delicate balance of power in post-First Wizarding War Britain.

I think a lot of it had to do with the fact that everyone sort of knew Voldemort wasn't really gone (hence all the "He-Who-Must-Not-Be-Named" nonsense) and was trying to hold off the inevitable second war as long as they could. It also explains how the Ministry of Magic was subverted so quickly, as you had plenty of people within the bureaucracy (like Umbridge) who were simply bidding their time for the proper moment to put their beliefs into action and plenty more willing to go out enforce anti-Muggle legislation when given the official nod to do so.

I can't speak for any new developments brought on by *The Cursed Child*, but I'd imagine that after the clear victory of the good guys at the Battle of Hogwarts and Voldemort's death, the victors are going to be a lot more aggressive about putting a stop to the blood purity bullshit than they were after Voldemort's first "death". JK Rowling even goes as far as to say that Slytherin's association with blood purity had waned if not entirely dissipated by the time Harry's kids are going to school.