Some friends of ours own a flat on Lewes Road. It has a huge wall, and was always being tagged and defaced. The owners got together and commissioned a piece of art from a local graffiti artist. It's had a couple of tags (which get painted over) but absolutely nothing compared to what it used to...
They did the second time!. But that is rather the point, street art (which is what the Bruno mural was) is great and is usually appreciated, it's the mindless tagging that pisses people off, it's like littering.
That's because there's a huge difference between street art and tagging. Most people at least have an appreciation street art, sanctioned or otherwise. You do know the difference?