I’d tend to agree with you poking after poking around the web for a while. However, I have conversing some Islamic people I know it appears that the matter is not so clear cut (it never is with religion) as I’ve been lent some texts that talk about this matter. Apparently several famous Muslim theologians including Seyyed Hossein Nasr, Mohammad Hashim Kamali and Sukri Husayn Ramic all are ( or were in the case of Nasr) avid narghile fans. My cursory readings those far seem to indicate that smoking is not a sin providing it is not intoxicating nor is tobacco unwholesome as it is a natural product given by God. Instead they condemn over indulgence/gluttony no matter what it may involve (i.e. food, drink, tobacco, jewelry etc) Nasr and Kamali both said that smoking can enhance quite contemplation and as a result stimulate an interest in things other then the profane.
I will have to read more to be certain but that seems to be the crux of the matter.