Yeah, I saw the line from the main character about how he doesn't blame her for what happened in the past. However, that doesn't excuse what she does in the present. Ellen has been encouraging the MC to take more missions, which is what Sonya also wants him to do, yet she still chases Ellen off. It's a selfish and hurtful move by Sonya that only makes the MC's life worse, not to mention what it does to Ellen. If Sonya wants the MC to move on and live his life, which is what she claims, she needs to sign the divorce papers and stop chasing away women that are trying to make the MC happy. Otherwise, she's just acting in her own interests.
As for the idea that they still love each other, I figure that the MC isn't in love with Sonja anymore since she never once crossed his mind until she literally appears out of nowhere while he's in bed with another woman. So I would've liked the option to tell Sonja to go get stuffed, as well as a chance to apologize to Ellen about the whole incident at some point in the future. Now, that's not to say that I'm against having the option of winning her back, just that I'd never take that option. I'm sure that there are a lot of other people out there that would love to see them back together, but I just see her as an impediment to his chance of happiness with either Ellen or Katie.