Perhaps people believe in Hell or destruction because of the number of Bible verses that completely oppose universalism.
“Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many.
Let both grow together until the harvest, and at harvest time I will tell the reapers, Gather the weeds first and bind them in bundles to be burned, but gather the wheat into my barn.’”
His winnowing fork is in his hand, and he will clear his threshing floor and gather his wheat into the barn, but the chaff he will burn with unquenchable fire.”
And do not fear those who kill the body but cannot kill the soul. Rather fear him who can destroy both soul and body in hell.
"41 The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity;
42 And shall cast them into a furnace of fire: there shall be wailing and gnashing of teeth.
"But the fearful, and unbelieving ... shall have their part in the lake which burneth with fire and brimstone."
" And whosoever was not found written in the book of life was cast into the LAKE OF FIRE."
"Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels:
For I was an hungered, and ye gave me no meat: I was thirsty, and ye gave me no drink:I was a stranger, and ye took me not in: naked, and ye clothed me not: sick, and in prison,and ye visited me not.
Then shall they also answer him, saying Lord, when saw we thee an hungered, or athirst, or a stranger, or naked, or sick, or in prison, and did not minister unto thee?
Then shall he answer them, saying, Verily I say unto you, Inasmuch as you did it not to one of the least of these, you did it not to me.
And these shall go away into everlasting punishment: but the righteous into life eternal."
“Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven.
People don't wish for Hell. It isn't pleasant, it isn't something we want to discuss, it isn't our idea of ideal, but it comes down to this, we don't teach what we want to believe, we teach the truth. The truth is not everybody is going to see the kingdom of God, which is why we evangelize, to say otherwise is to contradict Jesus. I don't know if Hell is a place, or a concept, or non existent. What I do know is that Universalism is contra Biblical