Why did the town of Gadarenes send Jesus away?

They were pagans (you can tell this because they raised pigs, which the Jews in the area did not do) and he had just destroyed a whole herd of very valuable farm animals for no apparent reason (from their point of view). That may very well have driven that farmer to destitution. For all they knew, he was going to destroy other farms next. Of course they pleaded with him to go away! They were afraid!

Fear.