Well, but if you ban Shariah law explicitly, how does it help at all? How do you prov that father was following Shariah law, and not just being an ass? He won't say it.
No, if you dislike a comportment, the way to go is not to ban some vague concept that may or may not correspond to what you want to see disappear. You ban the comportment. This means not only the stoning and cutting of hands, but also the fathers trying to force marriage or sequestrating people home.
Of course, these laws are hard to enforce, but "banning shariah", won't help at all.
And more to the point, other cultural and religious systems of ad-hoc law are just as bad. As mentioned, honor killings are cultural, not religious; but moreover, there are other tyrannies of religion which are just as bad. For example, the ultra-orthodox jews of Israel have similarly anti-women stances, as exemplified by stories like these:
http://www.huffingtonpost.com/2011/12/27/naama-margolese_n_1170655.html?ref=worldhttp://www.huffingtonpost.com/2013/08/01/ultraorthodox-protestors-smash-bus-windows_n_3689392.htmlSimilarly, there is also anti-women doctrine in much of Christianity; ranging from cases like FLDS, where women were effectively seen as property, to even the widespread expected subservience of women in more mainstream groups.
So it isn't so much a case of a few bad apples as it is a case of "Almost every apple in this crate has a varying degree of nastiness, as well as all the other apples in all the other crates."