These persons suppose that universalism is for the soft, for those who can't face the cold, hard facts of reality: namely, that God has horrible wrath against sinners which, if they do not repent, will damn them for the rest of forever for their iniquities. But we can play the psychologizing game in the other direction, as well.
I happen to think universalism is quite morally demanding, and requires a kind of strength that the ordinary person does not have. The universalist believes that, ultimately, the world is a good and favorable place for humanity, and this is because it is created and conserved by God, who is ultimately good and loves everyone. There are no ultimate cold, hard facts to face up to, because God's face is not cold and hard, but ultimately loving and good, even if harsh for the moment: Although he causes grief, he will have compassion according to the abundance of his steadfast love; for he does not willingly afflict or grieve anyone (Lam 3.32-33).
But this conception of the world is morally demanding, because it requires that we conform ourselves to God's image, who is good to all. If God is good to all and forgiving of every sin, then I can't have any excuses for failing to do so. If God loves all persons and is concerned for the good of everyone, then this same attitude of unconditional benevolence has to inform my thinking and my reasoning, as well. I can't reject anyone forever because God does not reject anyone forever. I can't be unconcerned for some persons because God is concerned for everyone. I can't be unwilling to sacrifice for the sake of sinners, because God was willing to sacrifice for the sake of sinners -- while they were still sinners.
St. Isaac the Syrian spoke of the merciful heart:
The pinnacle of universalist ethics, in my estimation, is this merciful heart. It is a transformation of the inner person, with the result that the pain of the world is felt personally, and supplication unto God for mercy and salvation results naturally. The person with the merciful heart wants everything to be well; she is tired and exhausted by the suffering in the world, and sees God as the world's only hope for rescue and restoration. This mercy extends even to creatures of the earth and to demons, those who do evil out of ignorance, those who are darkened in their minds. This may seem weak and possibly feminine to some -- perhaps an example of sexism in some theological thinking -- but that is a difficult objection to square with the truth that the fruit of the Spirit and the wisdom from above is a character of precisely the sort St. Isaac describes: gentle, merciful, kind, good, forgiving, peaceable.
Universalism is hardly wimpy; it demands an ethic of unilateral goodness which is beyond the strength of those who fancy themselves harder, stronger, in touch with reality because they believe some will be deservedly damned forever. They care about themselves and their "justified" sentiments of resentment and moral condemnation too much to open themselves to the demand of forgiving the wicked, of praying for bastards like the ISIS decapitators, to feel for the pain of those who deserve punishment. This is an excuse for them to be unforgiving and mean, for them not to make efforts and sacrifices for the sake of reconciliation and forgiveness. It is an excuse for them to be cold. Of course, it goes without saying that there are some who affirm the "traditional" understanding of hell as eternal torment, and who nevertheless are better than their doctrine, and have an uncommon goodness and compassion for sinners, even while they are sinners. But not all are like this.