Banksy will tell you it has a lot of coin value.
I must admit I'm also split on this one - your example is quite funny as is some others I have seen, but probably not as humorous if you have to remove it from your own wall and so that has the value of, well, of being funny, which is something in itself.
However, just seeing a rude word, or string of them, or just, for example, someone's initials daubed about in a dribbly trail of spray paint really only has value to whoever did it (we all want to leave our mark on the world).
But on the third hand there is that which takes skill, as most here know, I'm a useless artist much to my chagrin and so those who produce the fantastic stuff that you see in some places, to me, are very talented and it has value - again, this is speaking from not having to remove it from any of my walls.
So, as you can see, rather 50/50 for me, but although the number of reasons is the same, I think the content of those reasons, for me, tips it over into being that in a lot of cases it
