Only a confirmation bias on steroids could possibly explain how a man could look at our hero and see the wife, mother and housekeeper John needs to and does see Elly as being. Let's examine the traits that he explains away as being the result of some sort of hormonal disturbance so as to not face the fact that he doesn't know jackshit about her or anyone else.
First off, we have to contend with the fact that she doesn't seem to actually want to be happy. While I've never been one hundred percent certain that Elly actually realizes that happiness is a process instead of a thing, what I do know is that she doesn't actually really seem to want it. As I've said, she seems to be transfixed by the belief that happy, optimistic people aren't worth being around because no one could possibly taken them as seriously as she yearns to be taken. (Parenthetically, this probably means that Tom Batiuk's torrent of glurge comic strip Funky Winkerbean is one of her favourite things as it confirms her belief that the world is turning to shit.)
Next, we have to remember that she's so devoted to getting her processes one hundred percent correct that she never really manages to accomplish anything. This is why no one actually seems to believe that she does any housework; she's so busy trying to replicate a process she understood imperfectly that she never really had anything to show for her hard work.
We then have to remember that she has a low patience for doing things that bore or confuse her as well as things she isn't instantly good at; this explains not only her blowing off exercise regimens, diets and her academic career, it explains why she explodes in blind rage at machines that don't do most of the work for her.
Well, there's that and the fact that while she's too timid to do anything about the great big problems in her life, she loves to scream in a blind rage at minor irritants and non-events. The plurality of these Sudden Volcanic Hostility Events are touched off when people don't immediately do what she expects they will. Since she's the same poor judge of character John is, her family think of her as being pretty much always angry about something or other.
As I'll explain tomorrow, John and Elly are only married because of that last factor.