What if...
What if this movie was never intended to have a message? What if the screenwriter and filmmakers said "Let's make a mindless atmospheric thriller about a crazy bitch who waaaaayyy overreacts to her husband's admitted shortcomings as a husband"? And then did that. I am sure the film's critical reception would elicit a response from the filmmakers that would probably sound like "Hey...hold on...wait a second...that is NOT what I was going for at all."
I don't know if there have been interviews with anyone that debunk that possibility. But it makes the movie about a thousand times better when watching it like that.
For the record, I think the odds of this are slim. But it did cross my mind, and as I said, it made the movie better.