Opinion from other parents- Kid's Halloween costume

Let me get this out there before I ask the question:

I am not a 'beta', a liberal, wussy, fairy, or any other whiplash label guys on this board label people with in the pursuit of appearing to be more clever than they actually are.

And by the way, if you're not a parent you can save your opinion because it doesn't matter. Until you have had the experience of laying awake at night worrying about your kids you don't have a right to an opinion.

The Question

My 9 year old son has decided that he wants to dress up as Jason Voorhies for halloween (Friday the 13th character that hacks his victims up with machetes, axes, chainsaws...). My son has never seen the movie(s) but in talking with friends he decided that this would be a great halloween costume and I hate it on multiple levels.

1/ I have never been a fan of hacker/slasher movies. I think that they serve no purpose and seem to attract a following of kids that are pre-destined to be weirdos

2/ He's 9 years old. Put a damn sheet over your head like kids did when I was your age...

3/ Halloween has become too fricking extreme and morbid. It's not about ghosts and Frankenstein anymore. It has gone WAY too extreme with little kids exposed to things that are far too morbid for their immature brains. I went with him to the Halloween Store (a huge tent in the parking lot of the mall) and I was kind of overwhelmed by how gory and over the top it was... Seriously, is this what we want our little kids exposed to? How does exposing little kids to the concept of axe murder help those kid's minds develop normally?

It seems to me like it all has become too extreme and I wonder where it ends. Can we look forward to kids dressing up in a group Human Caterpillar costume in the future?

Anyway, I'm sick of popular culture dictating where we are as a society. Can't we at least try and keep our kids from this kind of overly-adult/overly-depraved weirdness?

Thanks.