its so unfair to my dad

My dad was death for almost 4 months or even more, and sometimes I still miss him very much~
Our house lost 1 member, who always used to in living room, his table, all the time and watched the TV for 24 hours without letting others people to watch. I miss his voice, his scary face expression, and his shadow.

Now I still wonder, why my dad didn't even been pushed to surgery room to try any luck. I knew that his situation was very critical at the time, but it isn't the responsibility for any doctors to try their best to save the patient? Especially when the patient already been knew that surgery or not also will die, why didn't try luck? Since even without operation, the patient also will die, why? It was so unfair for my dad, didn't even push to operation room, already been announced cannot being save? We watched so many dramas about the surgery, all of the dramas will try their best to save the patient, even its very high risk, as long as already do their best..

But why? My dad been announced cannot be saved? I will very thankful to doctor, if there was someone try to save him, even he might die too when the operation is on going, but at least I know there was someone wanted to save him. I miss him so much~