Dido thanks for that article. It was a good read.
I think the difficulty of executing public art may be the merest bit overstated, in general. In my experience, it's a flimsy excuse after the fact for being wildly out of touch with what the billpayers wanted to see.
I could rant about this at length, but I'll try not to. Suffice it to say, one of my local councils has a history of commissioning projects to beautify the district, getting something ugly in scrap metal with an alluring name, and reproving the public for their smallmindedness when they say, you spent how much of my council tax on this? After the furore has died down, they move the piece to somewhere it won't be seen, wait for people to forget about it and do it all over again.
My other local council has no such problems, and all their art projects are liked, lovely or simply ignored when we walk past, head down in mumsnet, because they engage with the public they have, not the public they think we should be. So projects are kept firmly in the realm of representational statuary.