Islam does not believe all faiths should be treated equally. Why should they be? If one has God's revealed truth, why should one tolerate lies that lead to the damnation of the faithful?
Sure, it's extreme--and scary. But isn't that the nature of most major religions--Christian, Muslim or otherwise. I have to agree with Buchanan here--if you believe you've found the one true God, why would you accept anything else? It's a frightening mentality, but from the perspective of the believer is makes perfect sense.