Why are people against graffiti?

I'm cool with graffiti. When I first started playing I wouldn't to others, but then I came to the forum and seen many people looked at it as helpful, because it's a payout on a building they wouldn't otherwise make money on. Then came the you can get up to five taps at friend's visits and I try that just to see how many I can get.
If I know someone doesn't like graffiti I won't but it's also hard to keep track of them. Most times I just want to get through my friend's list so I tap whatever it lands on.