Again, it's a Cultural issue. As a Russian in California, I get invited to parties with Russians in them, and some of those Russians are inevitably programmers, who complain about Indians not using basic hygiene, such as a deodorant. Others invent their own driving rules, and others fail to follow common sense courtesy customs, like not parking too close to the driveway, (Asians,) not holding parties past 10 pm every day during the work week (Latinos,) and so on. And it's not because they're bad people who want to harm their neighbors - it's what they were taught. The ones who are a minority in their communities adapt quickly, but if you're going to have a massive Latino community - why not party? Everyone does it!
Another thing I noticed is citizen engagement in politics - go to any city council meeting, and you will see a disproportionate amount of old white people. Most immigrants don't know that they have this power, and don't use it, and then special interest hire politicians to run for office, that are usually minorities, and corruption thrives; sometimes it results in white flight, although it can also be preceded by white flight. Some of the most corrupt cities are minority cities.
Then comes the linguistic aspect, which is more true in Europe than in the US. For a European, it's good to know five languages, but most immigrants hardly know more than three. While those numbers might be shocking for an American, the more languages you know, the better of a thinker you are, all else being equal. What about certain cultural aspects in schools? What about environmental preservation? Some immigrants are used to living in dirty slums, so they might not view a semi-clean street as an issue. Again, not out of malice - out of a lack of education. And Cultural Education takes time. That's why immigration should be restricted to a reasonable level, and why you need the natalist policies.
