There are all kinds of ways for a man to become a useless drunk.
Countless, infinite, unending ways.
Yep. And I kind of already said the why in this case - Nameless can see the Titans, and the Titans are hardcore. Apocalypse hardcore. Same Nameless Hero from the first game, 'cept now the Inquisition has no reliable supply lines, as something is making it near impossible for ships to get around without serious risk of being destroyed. Crippled Inquisition means they're consolidating their forces, and nobody can even see the Titans tearing the world a new one, much less fight them, if they're not out there. Steelbeard (Patty's father, as contrivance would have it) is rumored to have a way to traverse the seas without risk, so Nameless, Patty, and Carlos bunch up and head off to look for him.