Yes, at least Popper wasn't trying to "excommunicate" the "undesirables". He said it's perfectly sensible to tolerate even their intolerance, as long as you can counter it by reasoned argument and keep it in check by public opinion.

Popper at least has the decency to call it a paradox. This quote fully assumes that anyone that does not agree with the author on everything is intolerant and deserves to be excluded.

I have a hard time imagining that that's what Popper meant.

A purely intolerant society would necessarily also have to have some tolerance, or else it would collapse upon itself when there is no acceptable in group. Thus a natural stable zone in between total tolerance and total intolerance exists. Karl Popper's and Richard Rorty's views on tolerance are only rationalizations which attempt to position democracies intolerance as somehow justifiable in the name of "tolerance". What is stopping an autocratic regime from stating the exact same thing? They are intolerant towards x group or y idea to preserve tolerance to w group or z idea. Truthfully humanity has a certain capacity for tolerance, as defined by a zone between total tolerance and total intolerance. This capacity may have increased over time (although I would argue for technological reasons, not for cultural of philosophical reasons), but it will never reach total intolerance or total tolerance. They have both deluded themselves in the hubristic and elitist view that our shifting of the tolerance zone is in some way a testament to an increase in potential tolerance or tolerance "capacity", and have come up with such schizophrenic arguments which claim that a tolerant society must be intolerant. While natural law continues to prove them wrong and they themselves prove their positions wrong.