Hello what? Halloween isn’t even American, it’s Irish? I briefly (VERY BRIEFLY) looked up what Halloween is usually like in the Netherlands and it said yous only dress up, trick or treating rarely happens and that’s the only thing I could imagine being annoying.(obviously I’m not Dutch so correct me if I’m wrong)

You don’t have to like Halloween but at least be an informed hater

"How dare people have fun and wear funny costumes! These foreigners are replacing our glorious culture with their barbaric practices!"

You sound basically no different from a racist islamophobe who hates Eid. The only legitimate criticism of Halloween is the commercialization, but that's not what you're complaining about.