The question is (I think): must one be tolerant of intolerance in order to be tolerant?
Fine the answer is no
Unless of course you insist on this 'absolutization' of the words you seem bent on.
I do not have to be tolerant of X in order to be tolerant of Y. Only a ridiculously simple approach would require absolutism in tolerance.
I used to argue a similar point. If you want it to make sense do it like this:
Some people are under the impression that all tolerance is a good thing and that tolerance is inherently good.
They usually do so without thinking that the concept of tolerance can cover things that are quite oviously not good.
Not a mind numbing paradox or anything, except for the people who "absolutize" the word "tolerance".
Since people do in fact do so, it is a paradox.. for them.
But just between you and me they aren't right in the head.