is there anything to suggest that the 'weed' smoked by hobbits isnt more like cannabis than tobacco? looking at the film as tho gandalf and bilbo were potheads gives it a new dimension.
another point is that the smoking habit seems to have acquired a rather sexist demographic. i'm sure women in history have smoked pipes. not so in hobbiton.
i just noticed that word 'habit', certainly another credible etymology for the word hobbit given their very conservative way of life.