He won't or can't take on board her broken heart. There is part of him that just wants to start again and part that wants it all to be all right. He wouldn't be the world's first man to think that he can have a new wife while the old one and their children are in the background. Surely part of the problem is that he has replaced domestic happiness with political ambition. A man tired of domesticity goes out.
Domesticity is tiring, at least for men it is.
That's the difference between the sexes, between Jason and Medea. What Medea mourns is her lost domestic life - for her it was a golden life. The challenge is getting a modern audience to really understand what banishment will mean to Medea. We've lost touch with the idea. We know about refugees, we can imagine what it might be like to be awoken in the early morning by a knock at the door, marched off to Heathrow and put on a plane, but it is hard to capture just how terrible banishment would be for Medea.