It allows people the right to choose.
The smoking ban should be repealed and the right to smoke or not in a pub should be at the landlord/ladies' discretion.
Why not introduce categories for pubs, for example
Cat. A , No smoking allowed on the premises.
Cat. B, Generally no smoking inside but a room is provided for smokers.
Cat. C, Smoking pub , but a no-smoking room is provided.
Cat. D. Smoking allowed throughout the pub.
Of course smoking should still be permitted in external areas.