Sure, but the health effects are smoking are well documented and significantly worse than eating candy bars, or even most other poor diet habits that people have. In addition, cigarettes negatively impact the health of non-smokers that have the misfortune of having sustained contact with a smoker (for example, children) due to not only second-hand smoke but also the toxins that cling to clothing and other surfaces.
It would be different if smoking only affected the smoker, but as it affects the wider population (such as higher overall health care premiums), it deserves stricter controls.
1) From your link, "The study doesn’t cover the many other ill effects of breathing somebody else’s cigarette smoke, of course, which include asthma and possibly cardio-pulmonary disease." So not debunked exactly.
2) Penn & Teller are entertainers (and illusionists). They present controversial opinions for the sake of a TV show. It is not journalism and shouldn't be accepted at face value.
"but the health effects are smoking are well documented and significantly worse than eating candy bars, or even most other poor diet habits that people have"
Heart disease is a bigger killer than cancer in many countries.
It would be different if smoking only affected the smoker, but as it affects the wider population (such as higher overall health care premiums), it deserves stricter controls.