My own experience appears to be, and I say appears to be because I've learned that so often, what I think is the case isn't, that he is too afraid to deal with it, or something along those lines.
We went through an extended period, which started now about 2 years ago, when he really did seem to be very slowly starting to deal with reality. But then, despite many positive and self-aware actions, he DID go back to another avoiding activity. Or rather, another infatuation took hold.
I can wonder all I want if he started to deal with the demons, then the invfatuation/addiction took hold, or what, but I do know that the behaviour suddenly went back to what it was like ages ago.
As I know I've written before, it was as if he had been a recovering alcoholic, and then suddenly started drinking again.
It took me quite a while to come to terms with it; I had almost got used to being able to count on him for things with the kids and we even got to the point of being able to talk openly about some family things. Not quite r talk about us, but about the reality of how things were now.
Then shutdown. It took me months, though, to go dark again....; I guess that's normal, because we don't really know if it was going to be a blip, or a long descent again. It turns out it's the long descent.
That's the best I can come up with for my own situation.
I can speculate if it was a rational decision, but to me, that would mean speaking rationally about it, and that isn't the case, it was back to blame and monster.