I don't think a reasonable person would be annoyed by other people celebrating a secular holiday.
As far as Australia Day goes, I'd be confused as to why Americans are celebrating it, but I wouldn't mind it.
I don't mean Americans celebrating it. I mean every internet site you go on being covered in Australian flags and pictures of kangaroos and beer cans, and every web show you watch having Australia Day themed nonsense. All this going on for the two weeks or so leading up to the day itself. You don't celebrate it. No one in your country celebrates it or care if anyone else does. The same goes for everyone you know and pretty much everyone in your country. However, you're still hearing about it over and over and over again. That's annoying. Very much so.
I'm not sure how you got the impression that my problem is Halloween itself existing or people celebrating and enjoying it. That I'm fine with. It's simply having to incessantly hear about it that's the problem. Kind of like why the Bronies got torn several new ones a while back. It wasn't for liking the show or the show itself existing, it was for not ever shutting up about it for even a second. Same basic logic, really.
I read this thread for other people's annoyances, which tend to be more reasonable, entertaining, and less "I HATE EVERYTHING". Yours just happen to be in the way of the stuff I enjoy reading.
So... Don't read my posts if they're that offensive to you? I did say just say that, didn't I? If you really can't help yourself, this forum does have a block function. Just use that. In fact, why are you even responding to me? You know that's only going to make me write more oh so terrible posts of mine that wouldn't otherwise have existed, right?
All of the above will be far more effective than simply complaining to me about it. This thread's called Things That Annoy You, not Things That Annoy You and are Approved by Magus Silveresti. I shall post things that annoy me as I see fit, and you'll just have to deal with it.