Overkill - smoke 15 feet away from any door

It is almost a year now since Chicago adapted a no smoking policy for all public places. I say it is a good thing. Smoking is bad for your health. But what I think is overkill in the ordinance of Chicago is the fact that smoking should be at least 15 feet away from any door of a public place. So even the clubs or bars with outdoor decks or patio, smoking is not allowed since it is not 15 feet away from the door. That is just overkill. I can understand why outdoor restaurant, open stadium or public parks are non-smoking. But I don't understand why bars can't have a smoking outdoor deck.