I think the smoking ban is irrelevant too, at the time some pub owners were insistent on telling the world and their customers that there was no reason to go to the pub if you couldn't smoke, but I'm pretty sure that if the reason to go to a pub was to smoke you wouldn't be able to smoke your own fags in them, you'd need to buy them in there (just like I can't sit in a cafe and eat a packed lunch).
I don't think smokers were paying £3 a pint to just to have somewhere to sit and smoke their own fags, I think social interaction, fun, entertainment might have been why they were sitting in a pub smoking their fags. I don't think those same smokers are now resolutely sitting on their own at home with a fag and a can in lonely silence (any more often than usual).
Theres a general reduction in the number of people going to pubs because there are generally more things to do of an evening these days, whether you go out or stay in.
I mean its beer-oclock, its nearly the weekend, and here we all are on the internet.