“There are only two kinds of people in the end: those who say to God, "Thy will be done," and those to whom God says, in the end, "Thy will be done." All that are in Hell, choose it. Without that self-choice there could be no Hell. No soul that seriously and constantly desires joy will ever miss it. Those who seek find. Those who knock it is opened.”
― C.S. Lewis, The Great Divorce
That is just not reasonable. People CHOOSE to spend eternity in agony? That does not pass the test of reasonableness.
― C.S. Lewis, The Great Divorce
Sure they choose it, because they haven't experienced God yet. And that is because they reject even the mention of God, of truth, goodness, mercy and all the other attributes of Divine life. So they never give God a chance - or they experience God as foul because they are addicted to their own foulness.
But God, to me, must be the sweetest, most perfect experience possible. Therefore even those who recoil because God feels like foulness to them, will be purified by the experience, and eventually their own foulness will be cleansed by them from Grace, and then they will choose God.
So it's just a matter of time for everyone.
Unfortunately, some people take... a lot... more time than others...