That is how it is set up. That is reality. Whether or not it is "fair" is irrelevant. It simultaneously satisfies God's holiness and justice as well as his love and mercy.
God's offer of grace is what brings salvation. If, however, that grace is rejected, then that merciful offer has been rejected. To reject salvation is to choose damnation.
Those who believe in the Son will see life. Those who do not believe will not see life, but the wrath of God remains upon them.