Does it need to? The whole premise is that he hates his “relatively” cushy factory management job enough to think jumping in a volcano is a better use of his life.
For starters, he quit his job before the volcano opportunity came up. He choice was never "keep working or jump into a volcano."
He quit his job because he'd just been told he had just a few months to live, and didn't want to spend them like that.
Finally, he didn't have much money. He could either scrape by in his apartment for a few months, or go on a grand adventure and die just a little earlier than he would have anyway.