The paradox of tolerance was aimed at those who would with "fists or pistols" prevent others from sharing their views and was premised on the right of self-defense.
In historical context, it's seems squarely aimed at the paramilitary organizations of various movements popular around the 1930s or so who physically injured people for saying things they disliked.
Welcome to the messy uncodifiable reality of ethics and politics. You can pick a practical code with an exploit or you can pick one that lets you be cut down by anyone that doesn't go along with it.
Or you can try to fix the exploit. At least you can try to notice when people are exploiting it in the wild, which is to a first approximation "every time somebody cites the Paradox of Tolerance".
In historical context, it's seems squarely aimed at the paramilitary organizations of various movements popular around the 1930s or so who physically injured people for saying things they disliked.