Yes, the Jews were wiped out by the NAZIs. An evil crime by any definiton. So it logically follows that the Polish government should benefit?
Again, as Lizol indicated, those Jews were Polish citizens before the war.
what gives these organizations the right to the property?
It is normal longstanding law that assets with no heirs go to the Polish governeent—which had nothing to do with the Nazis.
Something like 9 MILLION non-Jewish Poles—were also murdered by the Nazis (more than the total number of Jews killed in all Nazi-controlled Europe)—and I have no doubt that their heir-less property also went to the Polish government.
Given that all kinds of people suffered 70 years ago under the Nazis, why should current day Jewish people be given advantages under the law?
The Holocaust was a LOT bigger than just killing Jews.