A google search on militant fundamentalist show most numerous articles on Muslims, Christians, and JewsOK, Hinduism seems to lead to (or be used as an excuse for) the same kind of thing, what with the recurring massacres between Hindus and Sikhs, and Hindus and Moslems, in India. But yes, the adamantly monotheistic religions have always "felt", to me, like the most liable to lead to this kind of shit. In world news, those massacres perpetrated by Hindus, there only seem to be about as many of those in a decade as there are by Christians or Moslems in a year, right?
Perhaps it is numbers but these are the most commonly used religions and their "standard texts" contain the necessary out of context snippets to incite the strong willed and weak minded.Well, looking at it from the point of view of "comparative religion studies", I'd say it stands to reason that monotheism leads to less tolerance and more bigotry: It has the "There Is Only One Right Way" thing even *more* built-in than other religions; that is what lies at the very core of monotheism AFAICS.
In polytheistic religions, one person can say "I worship Vishnu the most", and another would have to go, "Well I think Kali is the greatest deity -- but they're both gods, so I can't say you aren't just as much a Hindu as I am." (Substitute in Thor / Freya, Anubis / Set, Apollon / Hermes, Venus / Mercurius, etc...)
The step from there to realising that even someone of a whole other religion might still be human -- it seems a lot smaller than the same step from a monotheistic religion which only allows one single God, one single Truth, one single kind of True Believers.