It is probably reasonable for the average cafe-goer to expect dogs not be allowed inside cafes. Many establishments are quite small and it could get crowded very quickly.
However, outside is a different story. It probably boils down to the temperament and personality of the dog.
If you have a dog that snaps at people's ankles as they carry their flat white to a table, it is probably not a good idea to bring him or her along.
Also, if like me, you have a very friendly dog who likes to greet people, that could be equally as annoying. Most people go to cafes to catch up with mates or to have some quiet time.
However, a well-behaved dog sleeping in a corner of an outdoor cafe is probably not going to disturb anyone.
As usual, with these types of debates it is all about taking the common-sense approach.