People have a right to do what they will with their lives…
as long as what they are doing is not illegal/contrary to Torah, harmful to another person or the environment, and reasonably not harmful to themselves. The fact that someone still smokes in this day and age when only a moonrock does not know of the dangers of smoking and second-hand smoke,proves that such a person HAS no good judgment.
The reason Hashem probably gave us the Torah rather than allow us to rely on our good judgment to be good people, is that all too often people show very poor judgment, and judgment is a very subjective thing. We live in a day and age where people who are otherwise nice, fine, moral people think nothing of cheating on their taxes, paying cash so they don’t have to pay tax, and do assorted untzniusdik acts because they are “not hurting anyone.” Good judgment is highly overrated.