You're correct in your first paragraph and probably a quarter correct in your second paragraph. Just to be a bit more deliberate: poor communities have experienced high rates of crime throughout human history, it's a newly recurring phenomenon that high rates of crime are now happening in communities which are not poor, and it's a problematic sign for society. Without trying to crack open the entirety of human psychology and sociology in a comment on HN, a lot of people primarily gather wealth to build safety for their family, the entire reason that they become wealthier is to insulate themselves from the criminality that is common in poorer parts of their city/country/world. The fact that relative wealth is no longer as insulative as it once was is indicative of a wider ranging issue than poverty driving crime, and results in subtle shifts and cracks forming in society.
There are absolutely cultural drivers behind crime, as well as demographic drivers, and I am positing that a big piece of what's causing criminal culture to spread and shift is social media acting as a communications platform to spread a different set of social mores and standards than those that have historically enforced cohesion within larger society and reduced criminality in wealthier areas. Again, case in point, children of wealthy families in posh schools engaging in vandalize and theft of school property for social media points. Social media is nothing if not a cultural force that creates a new demographic that cuts across other lines, their user-base.