Very good point - it seems deeply misguided to make the primary focus on how these murders and suicides affected people after the fact rather than focusing on how they happened in the first place, and therefore identifying what factors and conditions might be changed to reduce the problem in the future. 

I believe it is political, and that that such a 'preventative' focus would identify facts and factors that are politically distasteful and difficult for (speaking frankly) progressive white people to accept. Most of these women ended up dead on reserve lands in deep poverty, and at the hands of their own abusive intimate partners, also Aboriginal. In other words the problem is largely intra-reserve and can't easily be pinned on externalities except the fact that the Federal Government's long-standing policy of incentivizing Aboriginals away from property rights and away from assimilation into modern Canada at large, has only increased Aboriginal poverty and social decline.