The wife is in denial about being sick which is why they have moved into the house in the first place so that she could get better. The house is suppose to be a sort of safe haven for her but she does not view it that way, in fact she even asks John if they could relocate to a different house and of course he refuses. By doing this, John reveals to us that he does not care about her opinion and that he doesn't believe she should be giving him ideas of what to do because he is too "dominant" for the opinion of his wife. This is they way men thought during this