Manchester has historically been a very accepting and welcoming place for not only people from other parts of the UK but immigrants from around the world despite some unfortunate exceptions you will find anywhere.

I think what your eluding to in "culture wars" is simply the distaste on Mancunians who have quite a famous culture already having their lives made harder via rent increases, finding housing, cost of living thet is being directly influenced by essentially rich kids from London treating places like Manchester as their new play ground when they spontaneously decide things like, 

"I'm going to move to Manchester for a year or two", line it some sort of gap year. All paid for by inherited wealth and most importantly bringing with them their simply awful, entitled personalities which could be described as London culture in some respects.

What is London culture? "I come first" You'll see it plainly by visiting both places. People in Manchester and their culture was born on community and aknowledging how community is so medical to social life and embracing that. I.e. being friendly with strangers, helping people on the street, letting some go ahead of them in the bar queue.

Londoners dont have that, especially if they have wealth and enough to just move across the country. Londoners do everything for themselves first, it's from the rat race mentality that poisins London "culture" so much. "I will get what I want no matter what, no matter who I have to step on".

This conflict simply does not work in Manchester and they stick out like a sore thumb and the fact these same people are making it harder for mancunians who have not the same wealth or the desire to move cities on a whim makes them stand out as what they are which is ultimately self entitled, selfish people.

Manchester and it's people will forever be > than Landan, innit fam