but at least you can quit cigarettes at any time and totally prevent getting sick from them.
Not really. I'm not sure if you're aware, but cigarettes contain this neat chemical called "nicotine". It does this cool thing called "getting someone addicted", and quitting it causes a great episode called "withdrawls". Oh, and even if you quit, you're still already permanently effected by those things I outlined earlier. Your argument relating to tar pits is still irrelevant and stupid.
Being genetically predisposed to have cancer is not relevant to our argument. Yes, I know quite a bit about cancer. If you've read the religious debates on this forum you'd know that my mother is afflicted with cancer. I also know quite a bit about Cigarettes; My grandfather had two heart attacks caused by smoking. The fact that he's alive is probably a miracle.
So do try to tell me how dangerous they are when people willingly smoke and get sick of their own free will when they can 100% avoid it by not doing it.
The same reason people do stuff like heroine. If you've ever talked to a smoker, telling them everything wrong with smoking is completely worthless. They already know it's extremely unhealthy, but they
don't care. You make this assumption that people are perfectly logical, when they really aren't.