You could make the same argument for atheism. Once I'm dead I'm dead, so why should I care what happens once I'm gone? I won't be affected.
What you're describing is a psychopath, regardless of their belief system. If someone would willingly leave their children/community/friends/whatever behind in a ruined world then they're an evil monster who, God willing, would actually go to hell.
You could make the same argument for atheism. Once I'm dead I'm dead, so why should I care what happens once I'm gone? I won't be affected.
What you're describing is a psychopath, regardless of their belief system. If someone would willingly leave their children/community/friends/whatever behind in a ruined world then they're an evil monster who, God willing, would actually go to hell.