Why is it ironic that the gambler killed himself in 'The Outcast of Poker Flat'?

He chooses the certain route of death over the uncertainty of life. Had he continued the struggle to keep the group alive, he risked trying his hardest and failing. Throughout the story, he remained calm and stoic, leading the group during the storm. However, he likely possessed some hidden weakness or feared the failure that would come with the group's demise.