If you want to actually change minds and protect society, declaring that bad ideas "shouldn't be heard" is the biggest mistake you can make.
So, just to confirm, hate speech is cool with you? "I think that people with trait such and so are less than human." I mean, it is just an idea, and any idea deserves to be dragged out in the open and heard!
Or is that not what you're advocating for? Because if you aren't, then you must agree a line on what is and isn't acceptable has to be drawn somewhere.