If they show no value for life, then there's nothing wrong in killing them off, as they obviously don't care. If they steal others' possessions, then they do not have value on personal property and their own may be destroyed or taken at will.
Until someone does something to show such, however, if they are tolerant of others' beliefs and do not attempt to force their own in place with the assumption that theirs are more 'right' (for example, the belief that they think the other person should die, and they feel that their opinion holds more weight than that person's opinion they should live), so long as they are accepting that others' beliefs can coexist beside theirs without conflict, then they are entitled to be left alone.
The only times yeu ever see a problem with this, anyway, are the times when one group just flat out becomes intolerant to large degree in the first place. For example, when the KKK decides to actually act out against black people. Sure, yeu have the right to hate them to the core... yeu just don't have the right to do anything about it. That's whot tolerance truly is... accepting that 'well maybe they're right, maybe I'm right, it doesn't matter, let's just agree to disagree and stay the hell away from each other'.
When that breaks down, that's when yeu get situations which cause the things yeu mentioned, such as the world not being nice enough for this to work... or the pirates...
In a truly tolerant world, christians would still hate gays, but would be like "well we don't like yeu... but hei whotever, do yeur own thing, yeu're not hurting anyone". They could coexist, and continue to provide benefits for each other, despite the fact that they may not like each other.
Instead, we have people who feel it is their god given right, nay, their duty, to enforce their beliefs upon others. They HAVE to enforce their hatred of gays, for they don't deserve to exist peacefully. They HAVE to go on a serial killer's rampage and kill 57 hookers they deem as 'evil'. They HAVE to go and just insist that everyone can't get along and there must be direct conflict...
Honestly, economically we'd be better off without such; as soon as yeu're intolerant of someone, or a group of people, those individuals can no longer purchase from yeu. They can't provide goods or services back to yeu. Yeu no longer have a working relationship because yeu just can't tolerate their existence, and are willing to shoot yeurself in the foot to show just how dedicated yeu are towards hating them.
Tolerance allows people who hate each other or don't agree to continue to exist together and still interact peacefully, and maintain a give/take relationship despite that fact. Once yeu loose tolerance, it just breaks down; either it becomes "take take take" or "I refuse to accept anything they have".
There are people out there that're so intolerant that they would sooner die of starvation than accept a meal offered freely out of the kindness of someone they just can't stand.
How does this help anyone? It really doesn't.
And yes, the world isn't that nice of a place. It sadly doesn't work. Because we really are so stupid that we will destroy ourselves and everyone around us just because we can't shut our mouths and get along.
Yeu don't have to LIKE someone to do business with them... that's tolerance right there. It works quite well, until one side goes and screws everything up.