And another thing - cigarette smokers (not pipe or cigar smokers nearly so much), the obese, heavy drinkers, etc. May cost the NHS more in the short term, but since they tend to die early they save the country the cost of looking after them in frail old age, so, over the whole population, it probably averages out.
And what about those who take part in dangerous sports? They're likely to be super-fit, but may suffer serious injuries. Do we charge them for their treatment too? Once you start charging some patients for their treatment, where does it all end?