Nobody has so far challenged the scientific fraud. NOBODY, NOWHERE, NOHOW. And if you think otherwise, you must not even know what an actual challenge to it would look like. Certainly not that worthless tripe from CATO or Jacob Sullum, and not that pathetic stuff in the tobacco growers' lawsuit against the EPA, or that worthless junk from NYCCLASH, either. And what on earth do you mean, "It seems only fellow scientists can do this"? Do you think it's just a contest of who can trot out the most Authority Figures? And where do you get the idea that anybody outside of the little clique of anti-smokers actually has any say in the matter, or that their activities depend on the majority approval of scientists in general? You obviously don't understand the science yourself, and are full of misconceptions.
....according to you.
The problem as I currently understand it with regards to smoking is (on the surface) that it is to be disallowed in all public spaces because SHS has been proven to be dangerous. The problem may also include (below the surface) a policy of disallowing because some people are convinced they know better than others as to how society (in public spaces) is best maintained or run, and are going to exercise their authority and influence to ensure their values are the most prominent.
I identify this as a problem because it used to be that one could smoke and produce SHS everywhere, and it seemed to be a non-issue, for the most part, for non-smokers. Yet, due to ideology of anti-smoking, it was presented as a huge issue for society, and something that needs to be changed. The change that has occurred from anti-smoking types is what I identify as the problem.
The challenges that I'm aware of to this problem are scientific, political and philosophical. Because we still live in a world where smoking is disallowed in most indoor places, then all of these challenges, regardless of how valid they are do show up as unsuccessful challenges. This would include whatever you currently identify as best method for challenging. It may be entirely valid, but it is thus far unsuccessful in overcoming the problem.
The scientific ones that have used scientific method to explain how not so harmful SHS actually is, strike me as the one that is most likely to be how majority could accept a change in course, where smoking is allowed in some (perhaps majority of) places, as the validity of these challenges could be tested by anyone that cares to understand the science and/or repeat the experiments done to date.
The political challenges are addressing life in public spaces beyond just SHS. Because they could have net effect of allowing private property owners to make own decision to allow smoking on their property, then I consider them valid. But because they are going for more than just reversal of SHS from hands of anti-smoking zealots, I'm looking at them as bigger than the noted problem. I'm interested in what else they are conveying and deciding on further validity from there. As I self identify as conservative, then I tend to agree with or find validity in these political challenges.
The philosophical challenges encompass the scientific and political and will tend to think through an issue (any issue) by looking at more than just one side. It is my preferred approach, but if I'm with a crowd that thinks a post like the one you are reading right now is way too long and could've been said in much fewer words, then I'm thinking the philosophical approach is not for this crowd.
Quit being dysfunctional. The point is that some people DO know how to attack the scientific fraud, and there have been lawyers willing to take on the case, but there was no money with which to do it. The big law firms that have the money to do it on a contingency basis were all sucked into the state lawsuit against the tobacco companies, and declined to take it on the grounds that it would be a conflict of interest.
"All sucked into the state lawsuit" strikes me as far more dysfunctional than anything I could possibly be doing with regards to the problem.