because you find it ugly? Because the city/HOA is asking? Because it's a political message you don't agree with (or don't want your house to get burned for it)?

So I have problems with the government but I blame graffitiers?

Because if graffitiers didn't degrade your property, you wouldn't have to clean after them?

As a renter, graffiti is great for me, it keeps property values down which keeps rent lower. And given that I don't aesthetically give a shit about it, it's win/neutral for me.