Just a quick clarification on this point. Warsaw is an authentic Polish city, filled with millions of Poles (who I am sure live ordinary Polish lives). I suspect that the people you were talking to may have been suggesting that the buildings in Krakow are more historic, because so much of Warsaw was destroyed either in WWII or by the Soviets.

But whether we like it or not, communism is a part of Poland's history and buildings like the Palace of Culture and Science reflect that history as do the avenues of drab apartment buildings. It may be worth seeing them before they are all destroyed.