If there wasn't such thing as being able to take a dog to a pub then we would never be able to go out for a meal whilst on holiday. We wouldn't ever leave our dog at the holidaycottages on her own as its a strange place and the dog would get anxious. You also don't know who's about the place etc. She is quite lively so we tend to sit outside in the pub garden even in February we've done this but personally I don't see anything wrong with taking dogs to the pub as long as they are kept on the lead and next to the owner. I've seen smellier people in pubs than dogs before
I can understand that you don't want a dog wondering around in a pub as some people are allergic or scared of dogs but well behaved dogs should be fine.