Gabe has all the recessive bad genes of the Connolly family. Lacking both Puck's determination and Finn's loyalty, Gabe decides to quit his job on the island and move to the mainland. This means that the family will lose their house and Puck and Finn will basically be homeless. Not that Gabe tells them this; they have to find out on their own.
Later, Gabe tells Puck that he planned on saving up enough money to bring them to the mainland too. Neither Puck nor Finn actually wants to go to the mainland though, so this is another bad plan on Gabe's part. Looks like that's one other thing Gabe never inherited: Communication skills.