Answer for question if Jews are fool or not ... I leave for other PF members.
Maybe they were fool that they called Poland their paradise ...
Maybe you are right that so antisemitic Poles accepted the biggest European Jewish society in Poland.
Maybe you are right that Scandinavians and Germans were so tolerant that Jews preferred to settle in antisemitic Poland.
Maybe you are right that Poland was not perfect especially when we notice that Jews achieved full rights in USA after WWII (like blacks).
as to Jewish assimilation ...
some were assimilated some were not.
From the Middle Ages until the Holocaust, Jews comprised a significant part of the Polish population. The Polish-Lithuanian Commonwealth, known as a "Jewish paradise" for its religious tolerance, attracted numerous Jews who fled persecution from other European countries, even though, at times, discrimination against Jews surfaced as it did elsewhere in Europe. Poland was a major spiritual and cultural center for Ashkenazi Jewry,
Karl Radek (1885-1939), Bolshevik politician
Jakub Berman (1901-1984), Polish communist, Secretary of PUWP (Polish United Workers' Party)
Józef Światło (1915-1975), colonel, communist, spy
(in post communist party)
Marek Borowski (b. 1946), Polish politician, a speaker of the Sejm
Berek Joselewicz (1764-1809), colonel during Kościuszko Uprising and Napoleonic wars
Szymon Aszkenazy, Polish historian
Gustaw Herling-Grudziński, writer
Tamara de Lempicka, painter (Jewish mother)
Daniel Libeskind, architect
How it is possible that some could make career some couldn't ? Maybe situation is similar to blacks in USA ? Or Turks in Germany ? Arabs in France ?
thous who wanted to integrate had possibility. Those who didn't want were living like those Jews form "fiddler on the roof"