Genuine question

Why is it that when a C-drama has a good script, nice dialogues, good cinematography, and is genuinely fun to watch, every character has to die? Seriously, why do they do this? I don’t have a problem with characters dying—heck, sometimes I think it’s a necessity for the story—but at least give some characters happy endings. I’ve seen this with Fangs of Fortune, and now that I’m watching Moonlight Mystique (please don’t spoil it for me; I haven’t finished it), I’m seeing the same pattern. In every arc, characters die, and no one gets to be happy —except the main characters, who merely have to wait for their turn to die by the drama’s finale.