Wifey is a bit cringe to me, mostly because I associate its usage with basic people, so I personally wouldn't ever use it. What I can't understand is the need for people like yourself to feel offence on behalf of women whose partners choose to use this word in spite of the negative connotations it might have once held, not because of it. Some Black people call each other nigger, some husbands call their wives wifey. Do you really think individuals such as yourself should be concerned with the semantics of pet names used between couples that are obviously not using it with the intent of being insulting?
My mate named his black labrador nigger. I'm fine with it.
And of course because language matters and is a major force in forming societal norms.