You know nothing about real estate and how property value works.
Say Chris Brown's neighbor puts his place up for sale. People see the grafitti which sticks out like a sore thumb in the area...and are no longer interested in the property at current value. So the property sits and sits and sits...the owner then drops the price. The house still sits. The owner the drops the price well below market value before it gets sold. THIS directly affects everyone on that block because when someone else goes to sell their house, they may have a hard time getting the price they want since a comp. in the area sold for far less. Do you understand how something that you think is so insignificant affects a neighborhood's property value?
Now...say there are a few Chris Browns in the area. What do you think will happen to property values?
I have no issue with folk wanting to be individuals and doing their own thing. That's fine...I only have a problem when that individuality affects other people.
I know how real estate works, and I'm saying claims of "reduced property value" are always overblown.
Will his graffiti affect some potential buyers? Yes.
Will his graffiti prevent other home owners from getting full value for their homes? NO
Some buyers might not like plain looking vanilla neighborhoods, so you could argue that all white homes reduce property value as well.
At the end of the day the "property value" argument is just a way to force people to conform. It is his home and his graffiti doesn't affect anyone else's home, any more than their decorations affect his