I would not hate ken if he does nothing to save hinami he is a damaged individual he probably has no love for anyone. I see all his personalities as different people and all had people they love. the one at the start had hide, hinami and touka and others at the cafe, haise had his Qs and akira. this one seems to love no one. and may not care for hinami so it is to be expected that he would let her die. but as many have said we have not had any insight of what he is thinking he is an enigma. maybe he does care and has a plan. but it is hard to tell right now. time will tell