Humans need water to survive, we don't need to smoke, next!
There's a link between drinking alcohol and fatality. That doesn't mean we should ban alcohol.
You're not making sense here, how can you say that "inhaling *some* tobacco smoke will not cause health problems" when at the same time *some* is the value for which smoking is dangerous? I'm not being clever, I really don't get it.
Ok think of it in numbers of cigarettes smoked. Assuming that second hand smoke is exactly the same smoke that the smoker is inhaling (it's not exactly the same but close enough) we could put a value on how much SHS is inhaled in a given volume of space, in a given volume of time and say that xSHS=smoking 1 cigarette.
If I smoke 1 cigarette in my entire lifetime will I suffer from any smoking related health problems?
Answer: No, none at all.
If I smoke 1 million cigarettes in my lifetime will I suffer from any smoking related health problems?
Answer: Hell yes.
You can describe both 1 and 1million here as "some". The more cigarettes worth of SHS you inhale the greater the chance of developing smoking related illness. Somewhere on the sliding scale there is a value between 1 and 1 million which means you are at significantly higher risk of smoking related illness. We don't know what this number is.
That's the problem, a lot of people go into public space every day, that would mean prolonged exposure. The people I'm "defending" here aren't the people who are exposed to smoking once every few days or weeks, but the ones who exercise their right to be in public space every day.
I am a smoker (yes really

) I don't have any problem at all with smoking being banned in public spaces indoors. I like public spaces being smoke free if I'm honest, and going outside to smoke isn't a major inconvenience most of the time. However UK law presently goes too far and bans me and my friends from our enjoyable past time of going to the pub for a few drinks, and enjoying a cigarette indoors along with our drinks and our conversation. It's not just an inconvenience thing either. Pubs where the majority of patrons smoke are seeing a sharp decline in trade and some are being forced to close.
Especially in low income areas these pubs/working mens clubs/bingo halls are social hubs where people meet and get to know the neighbours. If these places close entirely then local communities become more insular as there is nowhere to both smoke and drink, more people buy cheap alcohol from supermarkets and meet with smaller groups of friends in their own homes rather than go out to socialise.
I'm not arguing that we go back to how things were, or that smokers ought to be able to smoke in any public space, far from it.
I'm arguing that there ought to be some provisions in the law for smoking in some small fraction of pubs/clubs/bars. Also that banning smoking outdoors is almost as stupid as banning it altogether.