Responses
So one reason could be to give the story more deepth and it gives us a better understanding of what is actually going on. Since this is one with multiple POV giving backstory to the characters of the POV is actually pretty common. It also allows for a wider range of actions since we can follow the story without it being plotarmor. Also the chapter is his POV, that is why we only see his happy times with her. He cut out all the unpleasant parts. Like rose colored glasses, which could be why he did not think about his actions after marriage, because those are not part of his rose colored.
But also let me say. HE IS STILL An Ahole. (╬￣皿￣)凸
Why are authors doing this these days? Why draw up some sad sob tale for the bad guys to draw out sympathy? I do feel bad for him, I do but it changes nothing!!! And why are their POV so different? Like he erased the things he did to her or did those things happen after her first marriage?