The worst part about Ace hating Roger is that Roger probably would have given Ace everything he'd spent his whole life looking for.
Roger was genuinely excited to know he was going to be a dad. He made sure that his kid wouldn't suffer because of him so he asked Garp to take care of them. He loved Ace before Ace was even born and he likely regretted not ever getting to meet his kid. We could also tell he loved kids from the way he interacted with Shanks and Buggy.
But due to a series of unfortunate events, this was never to be.
I dunno, I just don't think Ace would have hated Roger as much if he'd had the chance to meet the real Roger. Not the Roger the world made him out to be.
Roger would probably not have been the BEST dad, but he would try. And maybe Ace would have hurt a little less...
