While D affects kids and yes, they would probably be happy if their parents stayed together, we know that's not going to happen in all marriages.
What we do know is kids fare better in these situations when the parents don't put the kids in the middle, don't blame the other parent (even subtly)and don't involve them (child) in something that's an adult situation.
That's where our focus needs to be. Your W isn't doing something TO the kids, yes, her actions, along with yours will affect them but it doesn't have to ruin them. I don't know your whole story but marriages aren't usually broken by just one act or one person. Your W may have tried in her way to work on the M, and most likely it didn't look like trying to you as I'm sure you may have tried and it didn't look like trying to her. That's how these things go.
Both parties have responsibility.
Stop keeping score. It's a no win exercise.
Accept responsibility for your part and let go of the blame. It's completely unproductive and the hurt and anger that doing that keeps alive will be telegraphed to your kids.
Take the high road.
Walk your path leave her to hers.
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss