If you hated your wife because she was a woman, and there was a history of violence in the local culture specifically aimed at women because they are women (examples might be: ‘all women are gossips’, ‘women made us unclean by touching us during menstruation’) then there could be specific additional punishments directed at you.
The additional punishment is to act as a disincentive to acts directed at a group just for being part of that group.
That is, if you hate your wife because she is always right and you are usually wrong, she earns more than you, and is a better cook, then your hate is personal and directed and the chance of murder is just like that of any other marriage.
If you hate your wife for none of the above, but because she is a woman, then your crime is impersonal, and you are a danger not only to your wife, but to all women (and transvestites and transexuals).
The greater punishment is to help protect all women, not just one in particular.
