Hell is a punishment, but it is also a choice. People choose to go to hell by not answering and obeying God's call in their life. God loves us enough to give us a choice, "free will" all humans have it. Therefore any actions that we take are ours. The consequences of those decisions if we do not seek forgiveness from God and obey him is hell, so yes it is a punishment but we go there on our own free will.