Can genetics help explain why some policies only work on some people?

Suzi Gage wrote an article describing a study I recently published in PLOS ONE that shows new evidence of why tobacco taxation policy effects may have stalled in the US. The novel aspect of the paper is that it is the first to explicitly examine whether genetic variation may partially explain the different reactions of people when faced with higher taxes.
Tobacco control policymakers face a puzzle in that some people seem not to care about high prices on cigarettes – they continue to smoke in the face of higher and higher rates. My paper suggests that genetic differences, which could be measuring differences in the pleasure people receive from nicotine consumption, may be partially responsible for the reactions (and non-reactions) we see in the world to tobacco taxes. The main finding is that people who are at high genetic risk of being a smoker seem to be unpersuaded by higher taxes.
Gage
summarised my paper as "poorly conducted research" that is a "gift to opponents of tobacco control". These are two different issues that I address in this response. For the first issue, Gage suggests there are a number of alternative explanations of my main finding. First, let me point out that research can be well conducted and at the same time be consistent with alternative explanations – there is a separation between the design of the research and the interpretation of the research. Alas, it seems that merging these two issues into a blanket "poorly conducted research" label is easier to do and may lead to more retweets than separating the issues.
The first issue that Gage outlines is that the model is incorrect – there are multiple ways of modelling a statistical interaction (genes and taxes), and I chose one. This is a fair critique in that it is impossible to know if the model is "true". Of course Gage has no evidence that what I do is wrong and suggests no specific alternative, but fair enough.
The second issue is that she claims that taxes and genes should not affect each other. Of course, this could be a fair point too, but it has no relationship to what I do in the paper – indeed it is a maintained assumption in my analysis.
A third issue raised is a list of "what I do not do" in the paper. Of course no paper does "everything" – but at issue is whether what I do is interesting and well done (rather than "poorly conducted") and this list says little relevant in evaluating her claim or providing an alternative explanation for my actual finding.
Finally, Gage suggests that other policies may also differ by state. Sure (but unlikely in the early 1990s in the US), but is she suggesting that I am finding differential effects of clean air laws rather than to tobacco taxes? Even if true (which it is not), does that really undercut the main question of whether genetics can shape responses to policy? Probably not.
This leads to a main point: "Imperfect" research is not the same as "poorly conducted" research. Most research is imperfect and some research is indeed poorly conducted. In my opinion, the issues Gage raises qualifies my paper in the former rather than latter category.
Gage then describes that even if my paper contains a "true finding", that does not matter because it is not policy-relevant, as governments will probably not genotype people in order to personalise policies.
A few responses to this narrow view. First, it is important for us to know why tobacco taxation seems to have stalled, even if the government will not genotype people. This is a basic point of policy evaluation – we want to know why policies work (or don't) and for whom. Indeed, my findings suggest that if tobacco taxation may not work for half the population, we might consider moving resources into other tobacco control policies (rather than putting more effort into a policy that may not work).
Another implication of the finding is that tobacco taxation works twice as well as we thought before, but it works really well on half the population but not well on the other half. That is good to know as a policymaker and as someone interested in the key determinants of tobacco use. All of this is lost in Gage's discussion.
Two final points. First, just because a finding can be used for evil by industry does not mean we should censor or question the finding, as implied by Gage's description of my research as a "gift". Some well done science will be used by "evil corporations".
Second, it is truly frustrating and disappointing that such an inflammatory headline ("poorly conducted research") was used in the Guardian to describe my paper without any discussion with me (or any others with relevant expertise as far as I can tell) to clarify the various mistakes and points of contention that Gage makes in her post. The headline was an affront to my professional reputation as a researcher and the post was an affront to the perceived quality of the Guardian.