The people of Galilee were anxious for the Messiah to come. They knew far better than most that they needed a savior. Keeping the faith in a pluralist place like theirs was not easy. They suffered discrimination from the hands of both the Romans and the Jerusalemites. There it could grow strong and unmutated by false teachings and philosophies.
Light shines the brightest in the darkness.
In Galilee Jesus was like a comet in the night-time sky. Everyone came to hear Him and only Him. He had no real competition. The everyday life of rural Galilean communities planting crops, tending sheep, fishing, caring for fruit trees and vineyards, gathering crops, and children at play all provide a common set of experiences upon which Jesus could draw to explain the nature and purpose of the Gospel. In short Galilee provided a set of common experiences which Jesus could use to convey his good news.