As ever the clue is in the title - this thread was about Sunday roast which would tend to attract family types. If there was no food, I don't think you would get the children in the pub.
Children do need to learn - and be told by their parents - how to behave in public. Where better to break them in gently than in a pub? Our first experience of taking children to restaurants was at the Orchard (before it went Thai), when my elder son was just three. Mercifully, he ate nothing but bread - the tablecloths were very white and crisp - no one else got a look in at the rolls, though. Now aged 8, with a brother of 5, I am moderately confident (you can't predict all eventualities) that they can behave in a civilised manner in a public place and demonstrate at least rudimentary table manners.
I fail to see why the fact that a pub serves food should immediately turn it into a glorified ball pool. Do adults not eat too?