What's the cause of widespread pub closures?

BBC News reports:

The rising price of beer, fuelled by increases in taxation, has been blamed for widespread pub closures - the Campaign for Real Ale says 14 are shutting down each week. In response, Forsyth says, consumers have taken advantage of cheap supermarket offers and switched to drinking at home.

I suppose we should be grateful that they mentioned the impact of tax rises, but has it not occurred to the author that the smoking ban might have something to do with people switching to drinking at home? Or has he considered this, and decided not to mention it?