Poles - by nature - do not like their neighbours
Well, the poll says that Poles "hate" Russians the most, but Russia isn't its neighbour, apart from Kaliningrad... :)
here it's being used (confusingly) as a translation of the Polish 'naród' which is 'ethnic group'
Polish people have always been a nation, even when they had no country, that's the definition, a group of people that share a common culture, language, religion, etc.
I'm not especially keen on the one that lives downstairs, though
Which one ? :)