I think you are deceiving yourself by restricting your dataset to those in your circles. Of course there are many smart and productive immigrants in Germany from all over the world.

I said I am not against immigration, but shutting it down for a period or restricting heavily might be worth it due to the potential risks that exist long term.

There's no real harm in trying that for Germany's voters, and by doing so you will also keep the far right wingers at bay.