Age restrictions are often appropriate. Children aren't fully responsible for themselves.
Generally, though, the issue isn't whose opinion is best, but whose matters. I'm quite sure the 'public health' types are correct that I am likely to cause myself damage if I smoke a pack of cigarettes every day. It's still none of their business if I choose to do so. The decision whether it is worth the risk is a value judgement that is properly mine to make.
...we were on a break