I'm 50/50 on this. I'm a smoker myself and absolutely HATE the non-smokers in the country I'm in now.
It's not because of the fact that they don't smoke or how they ALWAYS preach about quitting, but they are just rude. For example, they purposely walk past smokers or designated smoking areas just to make gestures or comments, even when there is clearly space to walk away from it or an alternative path.
I've been on both sides. I used to be an adamant non-smoker. I worked with colleagues that smoked and sat around with them after work. If the smell bothered me, I'd simply move to another area. I never made comments or preached to them about smoking.
Now that I'm a smoker, I do my best not to intrude on non-smokers. I'll go off away from people to smoke and throw my butt in a proper trashcan.
Everyone has their own addiction and smokers have their own reason for smoking. The way I look at it, if I'm stressed and decide to have a stick off on the side, that's better than resorting to alcohol, not knowing my limit, and potentially hurting someone when I'm not in my right mind. I know it's bad for my health, but I'm not going to quit until I'm ready to.
However, I also know that not all smokers are polite about it. There are plenty who just light up and slow smoke everywhere and then throw their butts on the ground so...I guess it's a two way street. If smokers don't want to be harassed, then don't be rude or inconsiderate. If non-smokers want to be respected, then you need to realize that there are people who want or need to smoke and give them space to do so.
I dunno, just my two cents.