Have you ever given a thought that would your girlfriend get along well with your family? Would you be spending your life with only your future wife or also together with your family?
I always think that a good wife should be someone who is able to support her husband in his career, be it mentally or physically. The minimal thing a good wife can do is to not pose any problem, which some people address as liability.
Of course, some guys are only looking at girls who can fill their emptiness; these guys are probably pushing out their luck and praying hard that their “sweet” wives can be truly sweet.
For me, I always look at people both externally and internally; sweet look without a sweet heart is not sweet at all.