Meh... Unfortunately, art has a way of being art for some and rubbish for others. I also cringe when I see sculptures of twisted, rusty iron all over my alma mater's campus... What the **** are those supposed to signify, anyway? (Doesn't help that my wife's cousin is one of the artists responsible for erecting that crap either).

But whether it's crucifixes dipped in urine, or paint expelled from the artist's posterior onto a canvas, artists always seem to try and find new ways to shock and disturb others. In fact, I would say that the castle graffiti is less shocking and disturbing than the examples I mentioned above...

Let the earl have his fun... As others have mentioned, it won't last forever. I can understand from those who are really into historical preservation, this just rubs the wrong way... But that's the way things go.

For those who must have historicity at all costs, I recommend not coming to Japan then, where most medieval castles have been retrofitted with modern interiors, elevators, electricity and running water, much like any other modern building. Sure it's a bit disappointing, but I'm not the one who has to pay the bills on the building and clearly someone figured that making a museum with elevators, drywall and a gift shop would get the tourists to drop more money than preserving the interior like it was in the 1600s.