It's both poverty and culture. The two can't be separated. You end up with a chicken-and-egg scenario: people surrounding the Roma know that the Roma they encou

It's both poverty and culture. The two can't be separated. You end up with a chicken-and-egg scenario: people surrounding the Roma know that the Roma they encounter are disproportionately likely to be the people who e.g. commit street crimes. This makes them act accordingly, by doing things like avoiding groups of Roma. This makes it harder for Roma who aren't committing crimes, whose behavior is not reflected in that estimate, to improve their culture or escape it. The non-Roma estimating that the average Roma is too likely to be violent to be worth interacting with think that for a reason, and we may call it "racism" or "bigotry" but it isn't unfounded. My sense is that it's very popular to point to external causes, causes that aren't blame-producing. "It's because they're poor"...well, maybe it's true that "If not for being poor..." but that's not the world we live in. By many accounts their culture (that is, the set of learned things they inherit) is set up to produce more poverty, crime, and social isolation. There are many groups of very poor people who do not have this problem, and who thrive in different circumstances. Accepting that there are things about their culture that would be better if changed or removed both reflects empirical reality and sets you down the road to finding a workable solution.