I don't get why Akali's Q is only able to proc on melee attacks now

I don't understand what the heck riot was thinking with this change, it slows down her combo and makes it really hard to trade in lane ever. But we have Kat which is basically like akali in her Q but her's can be hit by ability and melee attacks. So my question is why is Akali Q which doesn't even hit mult just one units just one, get the short end of the stick. I don't want's Kat Q to be melee only either but this just seems like really bad game machines. And it kills a lot of the flow that Akali use to have and makes her not enjoy to play currently!