I agree with everything you said (particularly the no maintenance part), but I think there must be another explanation as to why brick facades are so prevalent

I agree with everything you said (particularly the no maintenance part), but I think there must be another explanation as to why brick facades are so prevalent on southern Ontario houses. Other areas with similar climates and population levels (say, Minnesota) have much fewer brick homes. It probably comes down to tradition. In the old parts of any city, all of the 100 year-old houses have brick exteriors, as well as most of the houses built since then.