They have done this in order to get even with a world that does not care for them. “If you do not care for me – I do not care for you!”
If this results in everything being destroyed (including them) – so be it. It was not worth being saved in the first place.
The Christian influence here is noticeable. Christ died to atone for the sins of the world. And now everyone else will have to do the same thing.
Life on earth will end, but life in Heaven (which is much better) will go on.