This seems trivally easy to counter. Should the starving homeless person look at every day as a blessing? How about the sex traded slaves? "They were going to live another day, what did they have to be concerned about?"
I'm not trying to discount your point that you should have some gratitude or put things in perspective but happiness requires much more than just not dying. If nothing else your father had a wife and you as other hopefully joys in his life. Some people have no one.
Starvation and rape aren't everyday life concerns for Americans. Everyday life concerns are my car won't start, my date stood me up, will I get that promotion, I haven't got a thing to wear, the cabbie overcharged me, etc.
Going through any traumatic experience will change you in ways you can't imagine until it happens. It moves the bar to a point from which it will probably never fully come back, something will always be there to serve as a reference. To anybody who went through trauma looking at other people's lesser trauma looks like "trivialities". But it never works the same way the other way around. You can imagine lesser trauma but not really greater trauma.
> happiness requires much more than just not dying
Probably not for the people who don't have just the hypothetical appreciation of being alive but actually "cheated" death when it was all but certain.
I'm not trying to discount your point that you should have some gratitude or put things in perspective but happiness requires much more than just not dying. If nothing else your father had a wife and you as other hopefully joys in his life. Some people have no one.