Fire Code and appropriate fire ratings as you get closer to property lines is a very real thing, and this metal siding is one solution. It's not the only solution. They didn't "have" to use this specific siding, it was likely just a cheap way to meet the fire requirements.
The bigger problem here is that the kneejerk reaction is now going to be to try to regulate building materials. Some might say, "well just don't allow metal siding". But there is lots of
nice metal siding that's available.
Here is a very nice example of metal siding. Heck, there are nice and ugly examples of every type of building materials.
Keith, you're one of the forum members who complains the loudest about the bureaucracy of HRM, but then out the other side of your mouth you're saying HRM should be "ashamed" for allowing an ugly development.
Properly regulating taste takes A LOT of bureaucracy. We should not go down that route.