I Felt a lot of anger yesterday and today at the STBX for this. I own all this mistakes that led to the BD, but the D is on her. She's the one who chose this, she's the one who refused to be grown-up about this, the one who made it ugly. If this is so easy for her, then she's not the person I fell in love with and who needs her anyway?
I doubt it's been easy on her. She may act like it outwardly, but inside I bet she's really struggled with it. My W seemed really happy and satisfied when she moved out and was on her own, but months later she finally admitted that inside she was in a lot of turmoil and would often find a quiet place to cry alone. I was really surprised because whenever I saw her she acted like her new life was perfect.
I think a lot of WAS's move out and once they find that moving did not bring them the happiness they expected, then instead of searching within they think "oh, this didn't work, I must need a divorce to finally be happy." So they suddenly push quite strongly to get the D over with. But divorce isn't the magic bullet they want either. At that point they either start doing the soul-searching they needed all along, or they continue on in life unhappy and in total denial about why.