Yeah no idea what that part is about. The margins are absolutely in the alcohol, and the food is to get you to spend longer sitting there drinking with friends.
Some pubs successfully transition into a sort of trendy, highly publicized concept restaurant which charges a premium for food and essentially attracts well off restaurant customers who tend to drink more than average. I think that might be the model he had in mind. Most pubs won't be able to do this however as the market for it is only so big and it will tend to alienate their regular customer base.