I don't know where you live but I live in London and it's pretty damn fantastic most of the time, on Friday night for instance I stopped off in Brixton and had a really tasty meal at a small Colombian restaurant, the next day I ended up in a pub watching the Lions play before going off to meet some friends and visited a few more bars including meeting random people from across the world along the way. If London is a project then I'm not terribly concerned about the prospect. It's not a perfect city but it's still amazing in many ways.
Ah, these people won't complain because they don't have a choice just like you're not complaining now...
The British way of life (for all that vague nebulous term is worth) has always been a mixture of different cultures. Maybe if you can define what you're trying to save it'll be easier to determine what it is and indeed whether it is worth saving.