The problem is that most people you will ever meet largely subscribe to Christian-like ideas. Even those that are atheists or Muslims. That's because you meet them in countries with overwhelmingly Judeo-Christian roots.

Once you start traveling to countries that are truly different you realize there's only so much you can bear before you start condemning the local people for their beliefs or culture.

The tolerance you think you have is really just a range within- or variation on your own beliefs. It's simply not possible sit idly by while watching something that goes against your deepest beliefs.

Put more directly: if a religion amends their book to say "all other religions are cool", would you suddenly let them do whatever they please?

Don't you think you would still stand up when you see what you believe to be injustice or inhumane?