Live in a bunker with a psycho but safe and protected, well fed, clothed and with a comfortable bed, for the rest of you life?
Or
Try your luck with the aliens and chance of you surviving is slim to none? And possibility of resulting in a horrible death?
Given Howard's instability, I don't think that choosing to stay with him would ultimately result in being "safe", or even alive.
I'd take my chance with the aliens.
What happened in the final 15 minutes of the movie was pretty much impossible to survive in the real world. Michele should be dead but she was saved by plot armor. given those chances I'd have either stayed or waited for a better chance. The worst part was destroying possibly the only source of safe food in a miles wide radius. taking out Howard and then go exploring would have been best
share