So it's not your experience is it, it's just what you've been told. They said it was caused by cigarettes, how and why would be my interest, how did they know, and why did they conclude that. The point isn't that it's a tragedy, the point is that it's not respectful to your father, I don't think, to shame others for their choices. If I died because of my choices, and my loved ones made an advice article about why others shouldn't chose the way I wanted to chose, it's not honoring me or my choices.
If someone died because they ate bad, had a unhealthy appetite, or didn't exercise, or because they didn't wear a seatbelt, using their death to shame/urge others not to chose like them, is disgusting, it's despicable, it's just as selfish as you thinking that they are selfish for their choices.