Tbh no I don’t think Slytherin house needed to be developed further or shown as multifaceted or “not all bigots” or whatever because in the real world, nobody is hurt by “bias against Slytherin,” and in the world of the books, it’s made VERY CLEAR that bigotry and supremacy are some of the core founding principles of the house, which is not kept a secret from children, many of whom still want to be a part of Slytherin House even knowing what it stands for (one of the earliest things we’re shown is that you can say no to being in Slytherin, you’re absolutely given that option)
Whatever whatever I get that kids are brainwashed and conditioned to be racist by racist parents but to be honest at a certain point, them deciding to be bigoted or part of an inherently bigoted club being met with disdain and hostility which can only be avoided by Not Being Bigoted and Combating The Bigotry In Slytherin House is not a BAD thing, it’s making the consequences of their actions clear.
But it’s all a moot point because Slytherins are about as oppressed as unicorns and leprechauns, as they do not actually exist and literally no one can be hurt by saying “all Slytherins are blood supremacists” except perhaps the people they’re a direct analogue for, rich white trust fund kids who are upset that people assume they’re racist just because they’re part of a country club that still unofficially enforces a whites only policy