Age limits for children's media

Not my kids.  (Public domain photo from Pixabay.)

I've recently heard from two parents that I respect that they took their 6-year-old children to see the Avengers Movie - Age of Ultron.  I was a little surprised, as I've made ALL of the Marvel movies off limits for my 6 year old, much to his dismay.   He is a big Marvel/Avengers fan from Disney Infinity, and has seen a bunch of the old Spiderman cartoons, where some Avengers make an appearance.

I'm a Marvel fan as well (long time reader, nearly 2000 comic books still collected) and while I'm excited to see his interest, and want to share it with him, I'm also concerned.  The clips I've seen don't seem appropriate.

 My source for answers on all these age disputes, Common Sense Media,  says that the Age of Ultron movie is for teens age 13+ (although the user contributed reviews say 11 --and in a rare sense of solidarity, both kids and parents agree on the age.)

Here's what they say:

READ THE FULL REVIEW 

The biggest issue, of course, is the explosive, comic book-style violence, which includes nonstop destruction, fighting, weapons, flipping cars, imploding buildings, citywide devastation, and massive civilian casualties implied. There's also one sad death, as well as some kissing/flirting/innuendo/cleavage, swearing ("s--t," "son of a bitch," etc.), and celebratory drinking.  

So what gives?  Why would a normally reasonable parent let their younger kid see something that's not really inappropriate?

I have a few theories about this:

OLDER SIBLINGS
In both cases, the younger kid had an older sibling who would be within striking distance of the age range.  It's hard to limit a younger kid, especially when the older kid should be able to see something, and logistically, it would be difficult or patently unfair to separate the two kids.  Letting your kid see a potentially bad movie could seem the lesser of two evils than paying $50 for a babysitter so you can take the older kid by himself.

PARENTS AS FANS
When a parent is a fan, you want to share the thing you love with your kids, even if it might not be 100% appropriate.  Seeing the movie with your child might seem to ameliorate the problem, and the fact that the parent will be there to answer any questions/soothe any fears might also make it seem okay.

OVER THE HEAD SYNDROME
I think that parents might think that the bad stuff will go over the head of their younger child.  I'm pretty sure it doesn't.

MY KID IS VERY MATURE
Parents could think that their kid could handle it.

We're not perfect, but like any good superhero, we need to choose our battles.  We've use most of these rationalization sin the past (using older cousins instead of older siblings.)

While Avengers are out for us (much to my son's dismay)  we are considering taking him to see Tomorrowland.   (Which Common Sense Media says is for 10-year-olds, and contains some unexpected violence)    And we let him play Terraria, which Common Sense Media says is also for 10-year-olds. (While there is some violence, I think that the category of building games is generally a safe one for kids, especially if you can't interact with unknown people.)

We're also reading Harry Potter, although he's not allowed to watch the movies.  Not yet, anyway.

Ultimately, I feel its the parents choice, and it's a judgement call.  

What do you think? What are you letting your kids watch or play that maybe you shouldn't?