Compared to each other, some people are nice and some are mean. But compared to God, all people are not very good. All people need to be forgiven for their sins, not just "mean people." To be fair, God has to punish sin. God doesn't want to send anyone to hell. That's why he sent Jesus - to pay the penalty for our sins by dying on the cross. But, unfortunately, not all people are willing to admit that they sin and ask for forgiveness. They don't accept the payment of Jesus' death for them. So God lets them experience the results of their choice.
The Bible says, "No one is good without God. Every person in the world has sinned." No one has ever really followed God's paths or even truly wanted to. Everyone has turned away from God. All have gone wrong. No one anywhere has kept on doing what is right. (Romans 3:10-12)
Romans 5:16; Jude 1:4