The Polish PM is obviously saying the truth and shows a strong believe in nurturing home grown professionals rather than depending on immigrants workers in growing a nation's economy.
The aspect of security is valid too. Terrorism in any nation usually starts with unknown foreigners that came into the country illegally.
However, the immigration debate is a reflection of our collective identity as a society and the kind of future we want to establish. The discussion is one that calls for compassion, insight, and openness to other points of view.