Politics is "The art or science of government". If you wanted to be serious and say hardline that all art is about government, you would then have to ask which goverment, or how? Where? Or when people say this do they mean social politics? OR, do they actually mean philosophy, which morons regularly conflate the differences of?
I can make up a meaning for any piece of art, I can say anything I want about it, but it doesn't harbor credibility by default.
Intent is king, even if meaning can be defined by consensus. As lonely souls in the world, it's our job to find ways to say what we mean by expression (verbal, visual). By the way, my answer is "No". Of course not. Anyone who thinks or says this is actually retarded. Art is a tool of expression and communication. Art communicates intent, it's the artists obligation to do this as effectively as they can and consensus can tell you whether you failed by how much they misunderstand.
But a strong, clearly communicated intent can in fact invalidate what is perceived to be mass opinion- because the scope of mass opinion is naturally obfuscated and infected by malicious actions on occasion. At the end of the day and in a silly way it's paralell to IDpol and mirrors the opinions of the IDpol faith, and the root is to ask what labels mean (or don't mean) and how we are "allowed" to, or not define our own works.