Contributing further to the thread drift. Where does the assumption that Iran Air has to be dry come from?
It doesn't
have to be dry but it is dry and given the current government it will remain dry in the foreseeable future. You are right in saying that Christians for example can drink in Iran and I know from first hand knowledge that there is a thriving black market in imported booze as well as a lot of underground home made alcohol.
Alcohol isn't the be all and end all of travel but its availability sends a message to the travelling world which improves its attractiveness. Personally I don't drink when I fly but I do buy duty free for gifts and personal use. The duty free shopping in Iran's international airports is somewhat limited and pales into insignificance in comparison to Dubai or Turkey. That difference will act as a disincentive to travel via Iran as much as anything else.