That's a fair question. I guess for me, personally, I've seen countless studies on the harmful effects of tobacco; studies that convincingly show a cause-effect relationship of tobacco and certain cancers.
I have not seen those studies in regards to soda pop. Don't get me wrong, I don't think pop is good (as I'm drinking a diet coke as I'm writing this, lolol), but I just have not seen enough evidence that soda intake is the primary causal factor of obesity. I think soda sure doesn't help the situation, but it's not as big of a factor in obesity as tobacco has been proven to be in several cancers?
Does that make sense? (I'm being serious, not flippant with this question
)