Why did Gu Lei immigrate?

Because of development, because the country wants to develop its economy at the expense of Gu Lei's hometown;

Zhangzhou Gu Lei (1 17.50E, 24N) Port Economic Zone is located in Zhangpu County, east of Dongshan Bay at the southern tip of Fujian Province, including Gulei Port and Gulei Town, Xiamei Town, Du Xun Town, shaxi town, Caixia Forest Farm, Du Xun Yanzhangzhang Expressway and related sea areas behind it. The total planned area is 278 square kilometers, including land area 130 square kilometers and sea area 148 square kilometers (including shallow beach area of 55 square kilometers). The existing population of the Economic Zone is 6,543,800+350,000.