What makes Ove so mean?

I'm not expecting deep and complex character development in A Man Called Ove, no more than I expect character development in all but a very few films - and this novel is close to a screenplay in ova (ha) - but it's not exactly an action story, either - the title alone tells you it's a study in character. Part of understanding a literary character is getting a sense of where they came from, what forces built their personality, the back story, in other words, and Backman gives us in summary form Ove's back story: difficult childhood in some regards, mother died when he was quite young and father died when he was 16, leading Ove to abandon school - though he like and was good at math - and take a lifetime job as a railroad mechanic, a job at which he performed very well (as did his father before him) until he was made redundant, as the English say, just before the outset of this novel. What we see about his father was that he was an honorable, honest, hard-working man and a devoted dad; Ove inherited some of that - he was clearly a great worker and lived by his father's code of honor - we don't rat on people, and we don't fight. So I wonder what makes the adult Ove such a crank? He seems, from his childhood, as if he'd become a respected and well-liked retiree, but no - he fights with everyone, holds all kids of garden-variety prejudices and biases, is blunt in his expression of same, and comes very close to hanging himself in his apartment until interrupted - comic relief! - by some neighbors at the door. So there's a disconnect - how did he go from point a to point b, what happened that made him such a grouch and misanthrope? We do know that he deeply loved his recently deceased wife, thought she was too good for him - she must have tempered some of his eccentricities. But it's the eccentricities that make this novel; to the extent that it has a narrative shape at all, it will clearly be about his building relationships with the neighbors whom he holds in contempt, which is to say all of them. I don't know why they put up w/ him, honestly; maybe that's a Swedish thing (or a movie thing), but I think most Americans would ignore him at best and at worst be afraid of him, his temper and distemper.