To be fair it is a mixture of things as to why pubs fail but to continue to blame the smoking ban is a joke considering the rate of closure in the last couple of years is far higher than when the ban was initially introduced. Also as each country within the Kingdom have different laws with regards to the smoking ban means that it isn't really a prominent factor especially as Wales and Scotland, who have a much lax law the pubs have closed at a faster rate.
What we need to see is why certain pubs are flourishing. Firstly it is mainly the Freehold pubs and the Micro-brewery pubs that are flourishing or pubs that cater for certain markets (such as The Moses Gate or Dog & Partridge specialise in live indie/rock tribute bands).
Micro-brewery owned (such as Bank Top's The Tap) are working well because they are a niche pub that are filling a gap which is wanted by many locals - decent local beer with good taste and also serving guest ales, very little, or no, music and they are not tied to conglomerate breweries who charge both heaven and earth for the beers and the rent.