I would argue that in general we, who inhabit these British Isles do get on pretty well with each other as individuals. If people are friendly and have shared interests, be that nature, Grandchildren, golf , music, charity work then where they are from has little or no relevance. I have found that people who move into my area who complain about the climate, local accents, school curriculum, whatever, are generally pretty scathing too about the last place they lived - whereas the folks who rapidly make friends and become part of the community, often talk fondly about the place and friends they left behind.
We should not let one nasty encounter with a Welshman, Scotsman, Englishman, Irishman, Glaswegian, Londoner, fan of a particular football club colour our perceptions of a whole nation or area. We have simply met a nasty person - they exist everywhere but thankfully are vastly outnumbered by kind, caring, welcoming people.
If I say that I am a Scottish Nationalist, many people jump to the conclusion that I hate 'The English' this is so not the case. I am always careful to take aim at the 'Westminster Parliament', that undemocratic institution which rules over us from afar. I am quite sure that many (most?) people in the far corners of the UK share the feeling that their views are not represented there. Just as I know that regional differences in language were actively discouraged as much in Cornwall and Devon, Newcastle and Liverpool as they were in North Wales, Glasgow and the Western Isles. I believe that attempts to force each of us into a straightjacket of homogenous 'Britishness' alongside a 'divide and rule' policy which seeks to set one class or religion or nationality or locality against the other is deliberately pursued by the 'elite' to deter us from uniting against them.
Left to our own devices, stranded on a desert island, where we all had to pull together to survive, we would all get on together just fine.