She wasn't. She was at best hinting - again, something pretty much every communications book says not to do.
> "Hundreds, maybe thousands of times, my wife tried to communicate that something was wrong."
He doesn't go into details, but it's usually one of two things:
1. Nagging over what seems to be minor issues, and he is supposed to realize that there are deeper issues underlying.
2. Saying explicitly that something was wrong, but not saying what.
In both cases, she is lacking the communication skills to say what is wrong, and he is lacking the communication skills to make the path easier for her to say it.
He says this:
> The reason my marriage fell apart seems absurd when I describe it: My wife left me because sometimes I leave dishes by the sink.
The question is, how does she describe it to her friends? I doubt she says "I left my husband because he sometimes leaves dishes by the sink." And did she articulate that to him before it was too late?