Ian's infirmities as a man were absolved by his genius in our minds. But were they ever, for his wife? This is a man who got married before he was 20, intentionally had a child knowing he couldn't commit, suffered from clinical depression and made his small family suffer, cheated on his wife, lied about ending it once he was caught, told his wife 'But what does she have to do with us?' when asked about the woman, and eventually killed himself because the world was too much.
It's apparent that this world is not for people like Ian. I literally put the man up on a pedestal, as did thousands of people like me. But that wouldn't have changed anything for him, he was stuck in his own world. And that made me incompatible with the rest of the world. People who are stuck any which way are simply incapable of surviving. Ian hung himself. With all manners of prescribed drugs at his disposal, the man chose a painful way to go.
He watched a movie the night before. He talked with friends. Maybe he even called Genesis as he often did during sleepless nights, and sang Weeping to him. The next morning, his wife who was about to leave him, came into the living room to find him hanging.
As a man Ian Curtis was a lying bastard. An asshole who never understood why he was one in the first place. He hurt a lot of people. He hurt his own daughter. But he never enjoyed any of it. Throughout his life he tried to be normal. He tried to start a family. He tried to be a husband and a father. His music should have changed the world, but maybe the world got to him first. They were always at each others' throats.
There are thousands like Ian throughout popular history. An excerpt from Larkin's poem 'The Literary World' isn't so kind on Lord Tennyson.

Mrs Alfred Tennyson
Answered
begging letters
admiring letters
insulting letters
enquiring letters
business letters
and publishers' letters.
She also
looked after his clothes
saw to his food and drink
entertained visitors
protected him from gossip and criticism
And finally
(apart from running the household)
Brought up and educated the children.

While all this was going on
Mister Alfred Tennyson sat like a baby
Doing his poetic business.

I am not comparing Ian and Tennyson at all. I would never. But one sees the pattern after reading a fair bit about Tennyson's life. I'm sure we as fans will worship them for all the right reasons, one wrote great poetry and another made amazing music. That's all that should matter for us. The lovers of geniuses are simply unlucky.
Einstein, Time's man of the century, the first to postulate the theory of relativity, the one to convince FDR to build the atomic bomb, a man offered the chance to be the first president of Israel and considered the father of modern physics... married twice (once to his cousin), cheated on both of his wives with about 10 different women, and told his first wife to "expect neither intimacy nor fidelity." In his defense, he was honest. The fact that he had sex with his cousins, years and years younger than him, and even used his stepdaughter to deliver letters to ladies he wanted to have sex with changes little about the man in our eyes.
You have a musician, a poet and a scientist in this article, stripped of everything. You basically have three men who couldn't reconcile with the world.