For those of you who live in regions that have a Halloween culture, I can see where the Americanisation is annoying.
When it comes to culture...Use It, or Lose It. 'American' (or, more accurately, Hollywood/Walmart) Halloween hasn't overtaken traditional 'British' Halloween. It's simply filled an enormous vacuum.
Halloween was always a thing where my husband grew up, in the Hebrides. It never stopped being a thing. And, aside from easier jack-o-lanterns (you're less likely to lose a finger carving a pumpkin, than a swede) and, arguably, better treats (candy, instead of just peanuts), very little has changed.
A lot of other areas-- particularly more urban areas-- lost touch with these traditions generations ago. They were embarrassing, cringey, parochial, teuchter-ish, etc. Eventually, there was 'no such thing as society.' Without that, what happens to social customs?
People miss them, that's what. They're not even sure
what they're missing, but they know they're missing it. So they see stuff in TV and films, and it looks like fun, and there are companies chomping at the bit to sell it to them, nicely pre-packaged, but they don't actually remember what it
means. They don't quite get it.
Then, when it all comes out a bit wonky, they start blaming American culture for taking over.