How many other forums do we have which address the needs of 18% or more of our membership?
It will, admittedly, be useless for non-smokers but is that a reason to keep smokers from having it? I doubt that 18% of our membership flies Thai Airways or stay in Best Western hotels. Does that make these forums useless?
For that matter, are 18% of our membership either GLBT or Religious Travelers? If not, does that make those forums useless?
(BTW, the American Cancer Society has not shown any evidence that posting on a bulletin board which has a smoking forum exposes you to second-hand smoke.)