Overpriced costumes that claim to be on sale but are really just slightly less overpriced than normal.
Having to give strangers free candy.
Trying to decide your costume.
Those guys who pretend to be a prop to jumpscare children.
Candy wrappers everywhere.
You'll never eat all the candy.
The candy you do eat will get you sugar high.
It's almost always on a school night. I mean, it isn't this year, but that's not common.
Your candy will ferment in a bag until next Halloween.
Pumpkins are hard to carve.
The carving knives couldn't cut a grapefruit.
Halloween TV specials.
Halloween is the perfect time to rob people.
Blades in candy.
People who give out fruit.
People who give out dental products.
People who claim they're out of candy.
Walking around in an uncomfortable costume to get candy.
If you didn't buy a costume and just got a bag of candy and ate it you'd spend less.
Most candy really doesn't even taste good.
You feel guilty eating candy because you know it's bad for you.

The costumes are never scary.
Putting up decorations is annoying.

My halloween costume is totally scary!
Dan Hibiki from Street Fighter is quite the scary guy.
XD

THANK YOU.
I've been trying to make all these points to people whenever they demand why I don't like Halloween.
Seriously, I thought I was the only living soul that's come to these conclusions.