I live here in Sofia, Bulgaria right now and every first floor of every building has graffiti on it. Some are amazing pieces, others are not so good, obviously from less experienced artists. Of course there's the tags and shit too, which don't really add too much aesthetically, but obviously they have a functional purpose within the hip-hop/graffiti circle.
I personally like graffiti but there was a time when I didn't and I don't really blame anyone for not liking it. I wouldn't want some fucker tagging my building. But at the same time, graffiti adds character in my opinion, especially in an urban environment such as Sofia.