When Tonks and Remus die, it's like someone piled up all the tragedy that could ever possibly happen and laid it at their feet. Couple with big dramatic hurdle to overcome finally get a chance to be happy and then have it ripped away from them? Check. Young parents leaving behind an infant child who won't remember them, this repeating the cycle of events that Harry himself went through? Noble warriors struck down in their prime? Yup. Mrs. Tonks now having to deal with no only losing her husband, but her only daughter as well? You betcha. This is just a mountain of sadness and the two of them have already been through so much that it's devastating that they couldn't have had luck on their side, just this once.