I'm sorry that you feel like that. But if now they haven't unspoken things why their relationships should end? David talked that he always feel guilt in the others podcasts too. I think it is the excellent student syndrome. They both could hurt each other in the past. Why you think that David was an asshole all the time and Gillian was a victim? You see it like this?
Ask yourself a question. What, besides the X-Files, connects David and Gillian? Nothing. David and Gillian have different interests, different views on life and relationships, different friends and social circle, they live in different parts of the world. I'm sorry, but this is a bad basis for a real friendship. I don't believe David and Gillian are real friends. They have a good relationship, they are old colleagues and buddies, but they are not friends and even more so they are not family. These are beautiful words for fans. David and Gillian's relationship will continue if they meet in the future on some common project. But that's all. I never said that David was an asshole or that Gillian was a victim. I think David always cared more about himself, his comforts, his feelings, and he often didn't think about the people around him. This is not just about Gillian. David forced the producers to move filming from Canada to the USA and people lost their jobs. David quit the series and the producers were forced to quickly find new plot moves and Gillian had to bear the brunt of this decision and continue working. David said that the series could be continued without Scully, but he quickly "forgot" about this statement. David wasn't an asshole, he was a privileged male actor and Gillian had to fight for her rights as a female actress throughout the series.