I didn't actually see it that way. He said:
"We had a marriage that didn't work, this happens, with somebody that I love and respect, but to whom I shouldn't be married any longer," he said. "Ultimately, we tried. We tried, we tried because we had kids."
"I was like 'I can't leave 'cause of my kids, but I'm not happy, what do I do?'" Affleck said. "What I did was drink a bottle of scotch and fall asleep on the couch, which turned out not to be the solution."
He felt trapped that they were trying to stay together because of the children, he was unhappy, so he drank. I didn't see it as blaming - more like - he was in a dark place and turned to drinking and that was a bad "solution" - ie: not a solution.
I wonder if she had said the same if anyone would see it differently, I suspect they would.