Why would a man downplay all the contributions of his wife?

Why ask "why"?: I'm hoping i'm wrong but afraid i'm right... This is one of several features of the classic abuser and/or a marriage about to fail for other reasons. If she feels the relationship is worth saving, the wife can seek wise advice (for herself and/or the couple) now. The concern is that it will get worse and worse, with his keeping her isolated, ridiculing her, and eventually violence.