system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] Why didn't most Kryptonians leave Krypton before it blew up?

They were an extremely advanced alien race, surely they had the technology to go to other planets. Also, lets say they dont, they also have flight and they can breathe in space. Superman can go faster than light and he is an average Kryptonian.
gpt
Also in most every version of the origin, people didn't believe Jor-El's warnings about what was going to happen. They thought he was the Kryptonian Harold Camping, and just laughed at him or told him to STFU.

More varied are explanations as to whether Krypton had colonies or settlements outside of Krypton at all. Some have said that Kryptonians settled on other planets or moons near Krypton, but they were destroyed, either near instantly or gradually in the wake of Krypton's explosion (Kara-El Supergirl is a survivor of one of Krypton's moon colonies). In the Man of Steel movie they explained that the colonies simply collapsed and died out without Krypton.