You could plug-in Biblical equivalents in much of this rant. 'Fundamentalist' seems a blurry word, since it refers to the 'er fundament' and imples that the Basics are clear and unarguable. Of course every single person's idea of The Basics is quite her own.
So I think this is about: the ones amongst the homo-sap population who have become Certain (doesn't matter of 'what', at all - it is about personal-Omniscience, even among those who can't spell that).
Those who have pledged themselves to die for their Certainty (and even thrown in a 'soul' - of whatever personally-tailored composition) - are to be believed: these will not compromise, on into death.
So? Every fanatic and bigot has already eschewed the existence of Others and of their POVs. Thing is: how many Christians or Muslims or Zoroastrians are there, who are Certain?
Simple: lock up as many as can be extirpated. Kill those who won't be locked up - as is their wish. We'd best not confuse the sociopaths of any label, though - with the vast majority of people.
Now: will we trade Our Certain Ones for... Their Certain Ones - both matched sets to be placed upon an island (with the expected barbed-wire separation of 'differing flavours of Certainty', natch) ??
Ashton
PS - we may not nuke the 99.99? % to 'get to' the Certain ones.
To nuke is to join the Certain Ones - in their denoument, too.
Happy gamesmanship to us all. Are we adults yet?