Why is the movie "Tropic Thunder" rated "R" in the USA but only "14A" in Canada? Should it be Restricted?

Just saw the movie last night with my wife. ABSOLUTELY this movie should restricted. There is no way that children should see this kind of movie. My wife and I are pretty open minded and liberal but this movie would make even a prostitute or a stripper blush. Ben Stiller takes the use of sexually explicit language, swearing and graphic depictions of dismembered body parts to a new level. We lost track of how many times the Eff word was used along with the usual assortment of obscenities.

I must admit it was hilarious in several scenes and some of the characters were extremely funny but for an adult to bring a kid in to watch this kind of movie- Absolutely not!

A side note: The movie industry's rating system is a joke! The best way to rate any movie that is not R is to go and watch it first and then decide if the kids should see it.

We don't have restricted we have 18a, and we don't use it too often lol.