Many people criticize the graffiti, because it is painted on the street and most people don't consider it art this because make the streets dirtier.
On the one hand, there are people that consider graffiti a way to decorate the street, which can become something beautiful and attractive to see. Moreover, in my opinion it is something nice when the graffiti is not extravagant or exaggerated.
On the other hand, most people don't like that kind of art, some don't consider it art. People think that graffiti just the streets are dirty. Moreover, in my opinion I think that extreme graffiti can become ugly.In conclusion, in the centre of a city graffiti should not be painted, because most people don't like it. But in the outskirts of the city there may be graffiti.