It isn't really trolling, more of a valid question.
I personally can't think WHY someone would want to start - but that still isn't the point. If someone for whatever reason DOES want to, they shouldn't be shunned for it.
We all had our own reasons for picking up smoking, but with e-cigs around, there is no reason why people shouldn't go to that over cigarettes. There aren't 0-nic cig's, but there is 0-nic juice. If someone really wants to try it and is dead set on it, I would rather see them pick up a 510 with 0-nic juice than pick up a pack of marlboro's.
As I said, I can't understand myself why anyone would want to, but if for some strange reason they do, at least it is better than smoking. I do agree people shouldn't, but we aren't the ones to decide for them. Alls we can do is let them know what they are getting themselves into, and if they still want to after the initial skepticism we all show them, it is our responsibility to switch gears and help them make the best choice they can.