Thirty years ago, the Berlin Wall came down. Any art fan should celebrate that. Not just because it represented a profound triumph for free expression against the forces of authoritarianism and censorship, but because the thing was a bloody eyesore. The grey concrete was awful enough, but then the Berliners went and covered it in sodding graffiti.

Still, we should definitely celebrate. Because the fall of the Wall wasn’t just a monumental, wonderful moment in human history. It also makes an important point about art and protesting. Or, more accurately, the lack of it. And it starts with how artists have tidied up what the former GDR left over.

What’s remaining of the wall is now the world’s largest graffiti gallery. Some of the murals are great. Dmitri Vrubel’s ‘Fraternal Kiss’ of Brezhnev snogging East German President Erich Honecker is iconic and endlessly imitated. Birgit Kinder’s mural of an old Soviet Trabant car breaking through the wall is a powerful reminder of those who desperately tried to flee the East. Even though I’m generally sceptical of the value of graffiti, I can’t help but love them. Perhaps it’s my rampant Berlin-ophilia and an innate love of all things cheeky, but I think they’re a wonderful reminder of how far the city and her people have come in thirty years, and just how precious freedom can be.

But as much as I like the murals, they do make me uneasy. They’re certainly a brilliant celebration of free expression on an infamous example of its denial. But they also remind us just how useless all the East Berliners’ graffiti was when the wall was up.

Spray cans didn’t bring the wall down. The Stasi saw to that. Instead, amongst other things, it was a complex inter-relation of Mikhail Gorbachev, the Hungarian economy, a grocer’s daughter, the limitations of Marxist thought and a dozen other things. It wasn’t some east Germans defacing a wall. Symbolically powerful as it was, protesting through art made little or no difference.

What was true of graffiti in the old East Germany is the same of protest art today. We’ve seen a lot of it in Britain these last couple of years. I’m reminded of a photographic project by Swedish artist Jonas Lund in London earlier this year called “Operation Earnest Voice”. It was designed as an “influencing office” (whatever the hell that is) in the interests of reversing Brexit. You can agree or disagree with the politics behind it, but you can’t quibble with the truth that the whole thing was utterly pointless. The project may have been intended as a protest, but it ended up preaching entirely to the converted.

And that’s the trouble with modern “so-called” protest art. It fills the Royal Academy and competes for the Turner prize, but its actual impact is minimal. Why? Because it’s “protesting” to people who agree with it. Does anyone seriously believe that the high-ups of the London art world are Brexiteering Trump fans, with sidelines in supporting Benjamin Netanyahu and cutting down the rain forest? I didn’t think so. At least the Wall’s graffiti was standing up against something, however futile. Whatever the rights and wrongs of their opinions, contemporary protest art instead represents a collective self-indulgence on the part of an art world with homogenous political beliefs.

So, here’s a truly radical idea. Let’s cut the political posturing and protesting and go back to just trying to produce something beautiful. Simple as that. How hard can it be?

After all, the seemingly impossible does sometimes happen. The Berlin Wall came down, for example.