Basically, its Brexit. We have been so close to our European neighbours over recent years, and although we don't share a language we have most other things in common. That is now being torn apart. Also, we now have a government that seems happy to align itself with your outgoing administration. I live in a bubble of rural Shropshire, where things are pretty peachy (get that Americanism), but elsewhere its not so good.
It's thought-provoking, that. In my own mind, I've always placed Britain as occupying this sort of "one foot in Europe, one food in America" position. Don't get me wrong, purely British, just that you all seemed very open-minded to American culture and European culture, while holding yourselves wholly separate. I like that.
I'll say that I understand your concern - the several times we've visited, we've noticed more...Americanisms, I guess, and I don't just mean speech patterns, but giant Ford Explorers and Jeeps crowding the narrow roads, people walking less, seeing more and more product for sale there that we can get here, more people giving me the single middle finger than the usual up-yours reversed peace sign, and all the commercial development and consumerism...it all felt very...American.
I personally, just in a very general "freedom of movement" sense, hate the idea of borders. I don't mean that politically, I mean that as something beyond mere petty politics. The idea that just due to my happenstance of birth, that I'm tied to live and die in, except through much difficulty on my part, one country, whose borders I didn't help define nor ask to be a part of, is ridiculous.
Don't get me wrong, I won the birth lottery by ending up a white man in the US, but I'm one of those weirdos who just feels out of place, and I'd sure like it if I could just phone up Waitrose and say, "Hey, I like grocery stores, you're a grocery store, how 'bout giving me a job?"
The EU gave me hope that the planet was heading in that direction, and that maybe in a hundred years, folks could travel from here to there and back again without worrying about passports and waking up one morning and saying, "I'd sure like to shear sheep in Wales for a few years," wouldn't be a crazy, (nearly) undoable desire.
I'm just a hopeless dreamer, though. Head in the clouds, that's me. Sure does feel like we're all taking a couple of steps back, though.