Because that culture places women and non-Muslims as 2nd class citizens. This was not some random happening. They wont even deny it. Ask them. They are not ashamed of it.
They are taught that women are inferior. That Western women are even more inferior. So yes, the culture has a lot to do with this.
It's probably because you paint the whole culture under the same brush. Yes, fundy islamic muslims do that, but you'll be surprised to know that there are practicing Muslims that let their women dress as they wish and don't all want to click a detonator. When you point that out, be honest, it's not because you give a shit about the plight about someone over there, it's because you want to justify your hatred at them and justify invading those 'savages'.
Besides that, since when do conservatives give a shit about women's rights and gay rights. Spidey, for example, always posts mysoginistic shit and specifically married his woman because she 'knew her place'. Not exactly an unpopular position for American conservatives.
Edit: Speaking of spidey, totally forgot my sig.