The premise is that maximalist tolerance means tolerating intolerant ideas, and that there's a risk that a movement of intolerance can form which destroys the culture of tolerance. It suggests that rational discourse might not always lead us away from intolerant views, and maximalist tolerance could therefore be self-defeating.
You have to decide what's worth tolerating. You can't just say "can't we all be nice to each other" when there are people trying to celebrate an icon of slavery and white nationalism.
Where does this conclusion come from that rationality is so weak and our tolerant views are on such shaky ground that we have to prevent people from expressing intolerance?
So I'm not really sure what your point is. You seem to be trying to make a reductio ad absurdum, but it doesn't seem absurd to me for a community to be upset about a public statue of Che Guevara and demand it be removed.
You asked how it works, that's how it works