Pubs have been closed for a variety of reasons, often greedy breweries who realised they could profit more by jacking prices sky high or from the real estate if they did close. No doubt some felt the pinch of no smoking but by no measn all. My local, a chimneys pub, is fuller than ever.
Whist, as jtp points out, it is impossible to be 100% correct it does appear from what I can see that it is most likely smokers do not 'pay' for their habit, and certainly the many that smoke smuggles baccy dont, and neither do those on benefits as it is public money they are spending anyway.