Absolutely brilliant story.
I'd swear I felt the pain as that rock hit piggy's head.
I found what I thought was a fairly good comparison to the story.
In the UK, people perceive incoming immigrants to begin life often, abusing the tax system. Taking what ever they can get away with. Then they might have children here and more people from their culture may move here...Slowly the area becomes less desirable and soon that new culture may almost completely take over the area and take money/values out of it.
Then society here is forced to change, having certain documents in other languages, other religions and privilages may spring up in that area also.
The people that remain true to their ways/home can then be displaced much like the first formed group. You see, as that tribe's hunting culture developed when it had enough people, allot of the lawful tribesmen had no real option but to leave. Their old society was needed to keep them where they were. They could only remain here as forgotten and uncared for people, which was the unfortunate fortune of Piggy and the sole surviving member of the tribe.
I also came to realise the truth that, all of the values and morals I have learnt and value can mean absolutely nothing in a mind of a mob...no matter how valuable they might be.