Is there any scientific proof that smoking outside in the open air is bad for the people around you? As in damages their health? Tabacco smoke has to be concentrated and constanting breathed in to do actual harm- the conditions that, scientifically, have been proven to might happen indoors, buildings, houses, sealed cars- hence the ban.
I'm fine with that but not with an open air ban because somebody finds it stinky/unpleasent- which is basically what this amounts to. It's not a health issue but a social one, which is a weak basis for outlawing something.
Again, I'm not a smoker or even that sympathetic to smokers. But outlawing something- anything should be a big deal for an important reason.