I don't think we will ever understand voting for "pals" however it is explained. It is more than appreciation of language or familiarity with the song and its type. This might have been somewhat true in the past, but not now when nearly everyone sings in English and music is more pan-European (not including UK, though). The Nordic countries, for example, traditionally vote for each other, no matter what kind of song, in whatever language, they enter.
In England, say, most people wouldn't dream of voting for Scotland "just because" (if we all competed as individual nations and not UK) and certainly not vice versa! If I moved to San Marino I would never vote for the UK just because it was the UK.
I think people here are quietly patriotic and don't need to make a point of it, certainly not in the Eurovision Song Contest.