I'm with you. Graffiti is property destruction. It shows lack of respect for property rights. Respect for property rights is highly correlated with prosperity and that includes prosperity for those without property.
I think that this sounds good and is a sensible hypothesis, but it's far from clear to me that the corollary of prosperity for those without property is true in practice.
I don't know. Do you? If the latter answer is correct and it's backed up by quantitative evidence, then I guess that I have to accept at least some form of the corollary, although there are still games that one can play with measurement (for example, it's possible that being numerically richer in those richer settings can still result in poorer overall quality of life).