Consider this: in any period of human history there will be political tension of one kind or another. Art will be created in response to that tension. Some we remember, and some we don't.

The art we remember is remembered precisely because it adheres to generic standards of beauty in art, these being eloquence, daring novelty, or something else.

It's not about the message, but how the message is expressed that makes us cherish and remember art, whether it is explicitly political or not.

Yes politics are inescapable, and they color much of what we do, but what defines timeless artistic beauty is separate from the political motivations of the art itself. Otherwise we would not be able to appreciate ancient art whose political climate has long passed.

Further, I'd argue that because we don't fully understand the political climate for many ancient works of art that we cannot, in fact, fully appreciate that art within its ancient political context.

As an example, lets say some ancient work, e.g. stone henge, was in fact built either in support of or in protest of the practice of human sacrifice - wouldn't that knowledge enhance the work and our understanding of it?

The timelessness of the artistic beauty is still just a piece of the work as a whole.