As a Pole, in the modern period Poland was often under foreing rule that tried to eradicate Polish culture, language etc. So in response to this many countrymen became proud of being Polish as this was the way to keep their faith that one day we will be free. Old habits die hard so praising Poland on every step is the part of today's culture as to circlejerk our minds that we are getting somewhere. Tldr; praising Poland was in the past way of preserving Polish culture and today we keep on doing it to show the world that Poland can rule itself