There's some truth in that, and hate never got anyone anywhere.
But there will come a time, if it has not already arrived, when a tolerant people will see that mass immigration has a darkly negative side. What worries me are politicians that cause Germany to lurch from one extreme to another.
Lurching from one extreme to another (or avoiding it) seems to be an issue for many countries at the moment. Some are succumbing, some are not. It generally doesn't help to switch so quickly - things creep in under the radar that don't get the scrutiny they deserve and would not be supported by the population if they were looked at properly.
Anyway, let's hope Germany can resolve its issues. Catching the murdering driver would be a start.