[LaunchAway1]

> If those non-natives don't speak proper Dutch or with a heavy accent I could understand these parents, kids pick this up and it will influence their learning and future prospects negatively.

It's more complex. Learning in your native language has a strong effect in your ability to learn. For very intelligent kids this is no problem and may be actually good, but the aggregate effect is that non native kids will lag behind. Also immigrant parents tend to have lower education and worse jobs, with more demanding schedules and less time and energy to monitor closely their children and this also has a strong effect. A few inmigrant children is no problem at all but if there is a huge percentage then the academic level will drop. This will transform into just another force pushing segregation that will feed back the whole cycle.