I've been to Bondi and seen the "murals" along the waterfront. Some are reasonable to look at, but most display a serious lack of artistic talent. The problem most of these "artists" have is that no one has ever told them that they are no good; that they are failures when it comes to daubing paint on a surface.
I'm a fan of old fashioned murals, like the one here (scroll down to the third photo). It is well executed, and it has meaning to a wide range of people.
And it's legal, which is a big help.