I think that the article is a countervailing idea against the idea of the "paradox of tolerance."
If you accept the paradox of tolerance, then the truly intolerant are the ones you should not tolerate. Taken to its extreme, you can apply the paradox of tolerance to shun anybody that does not conform to ideological purity.
There is a balance to be found between the two extremes.
That's why I think paradox of tolerance should be applied recursively - as in, if in pursuit of the "intolerant" one is causing real collateral damage, then perhaps it's them who are the "intolerant" the society needs to get rid of first.
How much collateral damage? Any non-zero amount? [1]
Or does it only become a problem with it becomes some amount that's disproportionate to the damage that is allegedly avoided, as a consequence of those actions?
[1] If you believe any non-zero amount of damage is inappropriate, could you provide me with a single example of social progress[2] (or hell, any human, legal, or moral system) that was made with zero amount of collateral damage?
[2] Unfortunately, we have in the past, and currently live in a society where people need to scream, and shout, and break things for even the grossest injustices against them to be taken seriously. It's a natural consequence of self-interested democracy.
If you accept the paradox of tolerance, then the truly intolerant are the ones you should not tolerate. Taken to its extreme, you can apply the paradox of tolerance to shun anybody that does not conform to ideological purity.
There is a balance to be found between the two extremes.